Avatar
Please consider registering
Guest
Search
Forum Scope




Match



Forum Options



Minimum search word length is 3 characters - maximum search word length is 84 characters
Register Lost password?
sp_Feed sp_PrintTopic sp_TopicIcon
More .38-72 WCF research
sp_NewTopic Add Topic
Avatar
Member
WACA Member
Forum Posts: 4091
Member Since:
November 19, 2006
sp_UserOfflineSmall Offline
1
July 28, 2023 - 11:15 pm
sp_Permalink sp_Print sp_EditHistory sp_QuotePost

As I continue to prepare for loading up my own loads for a .38-72 rifle I’ve had for a few decades, I’ve run across some interesting information. 

First off, not all M1895 .38-72 barrels we manufactured to the same specifications.  

George Madis states (p.485 in my Winchester Book) states:

“Six groove rifling was standard for the model 1895 in all calibers.  Constant efforts to improved accuracy are evident upon inspecting a representative caliber in a series of rifles.  Caliber 38-72 W.C.F. rifles of early issues have rifling with one turn in twenty-six, with grooves three times wider than lands.  Rifle number 39532 has rifling as above while rifle number 42005 has grooves just a shade over twice the width of the lands.  Rifling, as states above, had grooves three times the width of the lands until the end of the 39,000 series. By the beginning of the 40,000 series rifling has one turn in eighteen inches and grooves one and one-half times the width of the lands.”

“Next in appearance is the rifling which has one turn in sixteen inches.  Issues over serial number 200,000 may have rifling which has one turn in twelve inches with grooves twenty-five per cent wider than lands, however, no rapid change was made until serial number 250,000 was passed.”

Kirk D. was kind enough to share his experiences on another board in 2011:

Another fellow who also owns an original 38-72 graciously loaned me an original Winchester 38-72 mould that he owned. With excitement, I casted well over 300 bullets. The naked bullets, before lubing, weighed 277. 4 grains, plus or minus 0.2 grains. The diameter, using wheelweights and a wee bit of tin, was .378”. The photos below show what the bullet looks like. The long nose-to-driving band ratio has turned out to be a bit of a problem, as I learned over the past month with a lot of work on loads.

It turns out that the bullet has a tendency to wobble slightly, judging from the slightly oval holes at 100 yards that I consistently observed. I tried to speed up the bullets to see if they would stabilize better, but found that the groups really opened up if I got much above 1,430 fps. The original black powder velocity was 1,425 fps, but black powder gives a pretty high peak pressure spike which obturates the lead bullet to seal off the bore. I found that slower smokeless powders just couldn’t produce enough pressure at 1,425 fps to do the job and I couldn’t go faster without groups really opening up. In situations like this, 2400 usually comes to my rescue as it gives a very similar peak pressure to black powder, all other things being equal. After some experimentation across the chronograph in my back yard, I settled on 17.5 grains of 2400 under the 277 grain cast bullet in my once fired Jamison brass. Let’s hear it for Jamison, they actually make 38-72 brass for a reasonable price!! I think I paid around $28 for 20 cases; I ain’t complaining about that at all.

I headed to the range just 8 minutes down the road that runs past our house. Out of curiosity, I decided to fire 5 rounds with the powder forward in the case (gun was level, but I tipped each cartridge nose down as I loaded it) and 5 rounds with the powder back (I’d tip the muzzle up while loading, and then level the gun). What an education!! In the photo below you can see the results, two different average velocities and two different groups with the same load. The powder forward gave an average velocity of 1,290 fps and the high group on the target. The powder back gave an average velocity of 1,425 fps and the low group, with one hole just below the paper. Range was 100 yards. The 1,425 fps group was 2 & 9/16” for five shots at 100 yards. The 1,290 fps group was 2 & 3/8” for four shots, but I wasn’t sure where the fifth shot was. The slower velocity had more oval holes in the back board, indicating it was clearly less stable, though the fast group still had slightly oval holes. Here’s the target ….

That lower group obtained with 17.5 grains of 2400 and the powder forward for 1,425 fps is the tightest load I was able to find after a lot of loads tried over this past month. This is not surprising, as the velocity is the same as the BP velocity and the pressure was very close as well. However, I am not happy with it, as I figure if the bullets are slightly wobbling at 100 yards, they will be worse at 200 and I want good accuracy at 200 yards. Furthermore, I cannot have a load with such position sensitivity. I don’t want to have to think about powder position when I am hunting, especially when it makes a difference of seven inches vertical between back and forward! The solution, of course, is filler, but I would have to use a lot of it with 2400 and I prefer to use filler with slower powders ….. but I can’t use slower powders because the pressure is not high enough to obturate the bullet and I can’t raise the pressure by going for a higher velocity with slower powders because the groups really go south fast with this plain base bullet.

Stabilization Problem: Winchester must have had a similar problem with their cast bullet. According to Madis, the 38-72 first came out with a 1:26 twist in 1895. Around 1904 they increased it to 1:18 and then later to 1:16. As near as I can measure, the twist of my rapid taper octagon barrel is 1:26, so I’m not optimistic I can get rid of that bullet wobble at 1,425 fps. With this in mind, I have given up on this bullet; the nose is just too long for the length of the driving band portion. The fellow who loaned me the mould has come to the same conclusion with that bullet in his 38-72. The long, narrow 277 grain bullet just won’t completely stabilize at 1,425 fps, which just so happens to be the velocity that seems to give the greatest accuracy. I am ordering a custom gas check bullet that has a longer driving band section than nose section. It should be more stable and I should be able to push it a bit faster up to 1,475 fps, which was the later velocity of the 38-72. Incidentally, Winchester quit making the 38-72 in 1909 and production of ammunition ceased in 1936.

Establishing a benchmark for this rifle: Finally, I wanted a benchmark accuracy. What is this rifle capable of with the right bullets? I decided to load up five more of my dwindling stash of custom swaged .3775 JSP bullets weighing 246 grains. The load was 28 grains of RL-7. Average velocity was 1,605 fps, but I found that with powder forward I got only 1,536 fps. The first shot ticked the top of the paper so Iowered the rear sight one notch and fired my remaining four rounds to get a four shot group of 1 & ¾” at 100 yards. This old rifle can be a tack driver with the right bullet! I am really looking forward to trying some gas check bullets in this old rifle. Here’s a photo of the JSP bullet and the target …..

I find the above very educational  and helpful.  It’s interesting to think about how Winchester likely struggled to stabilize their own bullets – which was probably the motivator to change the rates of twist as well as the width of the lands.

Next, what was in the early Winchester smokeless cartridges?

 

John Kort:

The early smokeless loading was 25 grs of DuPont No 1 bulk smokeless which has a similar burning rate to 4198…. at least in the 32-40 with a 165 gr bullet (17 grs DuPont No 1 = 1450 fps / 17 grs 4198 = 1460 fps).

John disassembled an early factory jacketed bullet cartridge:

The jacketed rounds containing Sharpshooter did not have any filler nor did the one with 25 grs of DuPont No 1 bulk smokeless which pretty much filled the case capacity. 25 grs of 4198 + PSB should be close to duplicating the DuPont No 1 bulk smokeless early factory capacity load.

In 1910, Winchester updated their velocities and show the 38-72 at 1,476 f.p.s. That is because earlier velocities were taken at 50 feet from the muzzle and beginning in 1910 they corrected them to muzzle velocity.

“Sharpshooter” was designed by Laflin & Rand as a dense powder to be used in b.p. cartridges, leaving plenty of airspace.

 

John’s thoughts about the length of the bullet as it intersected with rate of twist:

The Greenhill Formula for minimum rifling twist for stabilization indicates that for a .38 bore with a 1 in 26 twist, the max bullet length would be .85″ long.

While the Greenhill formula would get one close, it is not a positive equation in all instances.

For example, I have found that I can stabilize a bullet that is .96″ long in the 1/38 twist of my 45 Colt Marlin…but…the mv has to be 1,400 f.p.s. to do so.

Based on that, (Greenhill value of 170 instead of 150), the max bullet length in the 38/26 would be .95″…. or thereabouts.

Food for thought anyway…….

It would be interesting to trim the nose of those cast bullets back to an OAL of .95″ and see what happens……

 

So, Kirk, how many deer have you killed with your 38-72?

 

EDIT:

Oops, I see Kirk answered that question right on this forum in 2019 (very last post in this thread):

https://winchestercollector.org/forum/winchester-shooting-and-hunting/reloading-cal-38-72-for-my-winchester-model-1895/

Avatar
Kingston, WA
Admin
Forum Posts: 10589
Member Since:
April 15, 2005
sp_UserOnlineSmall Online
2
July 29, 2023 - 2:01 am
sp_Permalink sp_Print sp_QuotePost

Steve,

I am a big fan and proponent of using IMR 4198 in many of the old back powder cartridges. It is especially well suited for all of the 40 & 45 caliber straight wall cartridges. My high-wall in 40-70 Ballard really shoots well with a 326-gr hard cast bullet sitting on top of 24.5 grain of 4198. For myself, it is the universal black powder substitute, and it does not appear to be position sensitive inside the case.

Bert

WACA 6571L, Historian & Board of Director Member
High-walls-1-002-C-reduced2.jpg

Avatar
Member
WACA Member
Forum Posts: 4091
Member Since:
November 19, 2006
sp_UserOfflineSmall Offline
3
July 29, 2023 - 2:22 am
sp_Permalink sp_Print sp_QuotePost

Bert H. said
Steve,

I am a big fan and proponent of using IMR 4198 in many of the old back powder cartridges. It is especially well suited for all of the 40 & 45 caliber straight wall cartridges. My high-wall in 40-70 Ballard really shoots well with a 326-gr hard cast bullet sitting on top of 24.5 grain of 4198. For myself, it is the universal black powder substitute, and it does not appear to be position sensitive inside the case.

Bert

  

Thanks for that Bert – very helpful.  I have some on hand here.  

Avatar
Member
WACA Member
Forum Posts: 1537
Member Since:
May 23, 2009
sp_UserOfflineSmall Offline
4
July 29, 2023 - 6:29 am
sp_Permalink sp_Print sp_QuotePost

steve004 said
As I continue to prepare for loading up my own loads for a .38-72 rifle I’ve had for a few decades, I’ve run across some interesting information. 

First off, not all M1895 .38-72 barrels we manufactured to the same specifications.  

My research into Winchester Reloading Tools may shed a little light. Hopefully one day even more can be determined. That said, Winchester also experimented with the style of lead bullets they used for this round.

I find the above very educational  and helpful.  It’s interesting to think about how Winchester likely struggled to stabilize their own bullets – which was probably the motivator to change the rates of twist as well as the width of the lands.  

This is also likely the reason that there are two style “Lead Bullets” used by Winchester. I’ve conversed with Dan Shuey on this and other like calibers in the past. Dan pointed out to me that he noted two different style lead bullets in his Volume 1 Head Stamp book.

It notes 1st style “Headstamp Variation “A” – Bullet Description “Lead Round Nose” – Case Description “Brass” – Primer Index # “#1 Oval BR”

And the 2nd style “Headstamp Variation “A” – Bullet Description “Lead Round Nose BELTED” – Case Description “Brass” – Primer Index # “#1 Oval BR”

A drawing of the different styles are on page 309 of the book.

I’ve heard rumors that their are Winchester Factory 5th Model Bullet Molds with two different cavities for the 38-72, but have yet to find a “BELTED” version or a 38-72 Mold with a different cut cavity from another one that I have. But this wasn’t the only time Winchester did this with their molds. Bullet Molds in 30 W.C.F. Short Range in 1896 had a 100 grs Round Nose Cavity, where Molds made after 1904 have a 117 grs Flat Point Cavity. I have both in my collection, other than looking at the cavity, they’re marked the same with the same caliber stamp on the handle. 

Kirk D. may have used an different style cut cavity 38-72 mold than what Winchester optimized the barrel for in his particular Model 95. Which may explain his “loose” rounds. Maybe the belted version of the bullet is more stable? Wish I could say either way? Would be good to know and find out.

Sincerely,

Maverick  

Avatar
Member
WACA Member
Forum Posts: 4091
Member Since:
November 19, 2006
sp_UserOfflineSmall Offline
5
July 29, 2023 - 12:31 pm
sp_Permalink sp_Print sp_EditHistory sp_QuotePost

Maverick – thanks for all the information and thoughts.  It is an interesting topic.  Retrospectively, we are trying to reconstruct the reasons behind various changes Winchester made.  They were clearly going through a refinement process.  We know they did not want to be known for selling inaccurate rifles!

Avatar
Eastern Iowa
Member
WACA Member
Forum Posts: 270
Member Since:
February 22, 2021
sp_UserOfflineSmall Offline
6
July 29, 2023 - 2:14 pm
sp_Permalink sp_Print sp_QuotePost

The naked bullets, before lubing, weighed 277. 4 grains, plus or minus 0.2 grains. The diameter, using wheelweights and a wee bit of tin, was .378”.

In my opinion, speed and weight were not the issue here. Bullet diameter was too small which is what was causing the tumbling. It probably would punch up with black powder. Smokeless loads are going to require at least a .380 bullet .381’s probably will work even better. With black powder you should be able to go 255gr to 270gr. I believe 270 was the factory load. The M95 book says twist was 1-22 with a .379-.380 groove size. I’d stick with that info until I personally checked the twist on my rifle…and slugged it as well.

Avatar
Member
WACA Member
Forum Posts: 4091
Member Since:
November 19, 2006
sp_UserOfflineSmall Offline
7
July 29, 2023 - 2:57 pm
sp_Permalink sp_Print sp_QuotePost

Brooksy said

The naked bullets, before lubing, weighed 277. 4 grains, plus or minus 0.2 grains. The diameter, using wheelweights and a wee bit of tin, was .378”.

In my opinion, speed and weight were not the issue here. Bullet diameter was too small which is what was causing the tumbling. It probably would punch up with black powder. Smokeless loads are going to require at least a .380 bullet .381’s probably will work even better. With black powder you should be able to go 255gr to 270gr. I believe 270 was the factory load. The M95 book says twist was 1-22 with a .379-.380 groove size. I’d stick with that info until I personally checked the twist on my rifle…and slugged it as well.

  

Good thoughts Brooksy.  I would assume that black powder was used for the initial development of the .38-72 cartridge. The black powder pressure curve likely allowed the lead bullets they were using to bump up sufficiently to enable less less wobble and greater accuracy.  A short while later, enter smokeless powder.  The equation changes and hence Winchester’s moves to change land size and twist rate.  Next, enter jacketed bullets.  Another change in the equation.  

Avatar
Eastern Iowa
Member
WACA Member
Forum Posts: 270
Member Since:
February 22, 2021
sp_UserOfflineSmall Offline
8
July 29, 2023 - 3:07 pm
sp_Permalink sp_Print sp_QuotePost

Jacketed bullets were going to be my next mention. Although I’m not sure why Winchester would drastically change things because of them. Probably lots of folks still hung on to black powder loads for the 38 72 so any changes ruining black powder loads probably wouldn’t have went over well with owners.  In the end it’s all for not as they dumped production in 1909 to join the new world of high-performance smokeless cartridges. 

Forum Timezone: UTC 0
Most Users Ever Online: 778
Currently Browsing this Page:
1 Guest(s)
Top Posters:
clarence: 6133
TXGunNut: 4848
Chuck: 4509
1873man: 4255
steve004: 4091
Big Larry: 2287
twobit: 2280
TR: 1686
mrcvs: 1652
Forum Stats:
Groups: 1
Forums: 17
Topics: 12474
Posts: 108270

 

Member Stats:
Guest Posters: 1725
Members: 8699
Moderators: 4
Admins: 3
Navigation