1952 Model 70 in 270 Win|Winchester Hunting, Shooting & Reloading|Forum|Winchester Collector

I set the primers at .008″ below flush because world class shooters have tested seating depths and have found that this is a good depth.  The main thing to remember is, at a minimum, you should seat the primers so the cup is bottomed out.  This assures that the anvils are all touching the bottom of the pocket. I have a gauge that measures primer pocket depth, primer thickness and final seating depth.  The seating tool I use can be adjusted .001″ at a time.

My next thing is I’m going to find hard jam on the bullets by seating them long and forcing them into the case by closing the bolt. When doing this you have to have your neck tension already figured out.  Hard jam is not where you want to seat and shoot your bullets.  Some world class shooters seat their bullets at hard jam minus .020″.  I’ve tested this method and it does not pose a pressure issue but didn’t give me the best results.

After finding hard jam I usually start seating the bullet into the case to the point my stripped bolt will just drop on it’s own.  This is touch.  But, I’m not sure if the controlled feed on the Mod 70 bolt will do this?  I need to pull the firing pin and see.  If not I will take a fired case and tap and thread the base and use the Hornady Lock n Load tool to find the lands.  So somewhere less than hard jam the barrel will tell me what seating depth is best.

After I test the bullets for touch I will use a powder charge that is safe and a bullet seating depth that will keep the case tight against the bolt face so I can fire form the cases.  When fire forming you are only concerned about getting the shoulder to lengthen to the point it touches the inside of the chamber.  It make take several firings.  If not done properly your cases may stretch at the base and then can lead to case head separation down the road.

After fire forming the real load development can start.

I know many will think what I’m going to do is overkill for hunting purposes but everything adds up and your ES/SD and group size will improve.   How much we will have to wait and see.

Thanks Lou for the encouragement.  I am going to post my progress as I did for the Lee Navy.

One problem I have encountered is the safety is stuck in the fire position.  I keep messing with it and got it centered a couple of times.  I took the firing pin assembly out and cleaned it.  The fire control system on the target guns get a lot of work done so nothing impedes the forward progress of the firing pin.  Areas get clearanced, polished and springs are chamfered and deburred.  Springs get changed on a regular basis and the amount of firing pin fall is checked.

Last night I took a Hornday 145 gr. ELD-X bullet and jammed it into 5 cases to find hard jam.  Base to ogive of the round ranged from 2.691″ to 2.694″.  The difference is due to the inconsistency of the neck thickness causing different neck tensions.  I’m going to use 2.691″ as my starting point. When fire forming I will use something less that 2.671″.  At this point I know I’m in the lands but don’t know how much.  I need a fire formed case to tap and thread for the OAL gauge.  With this I can find touch.  You need a case that the shoulder is touching the inside of the chamber to be accurate. If not all your headspace measurements will be off.

I mainly use Lapua brass when it counts.  Lapua supplies a lot of brass for the war effort so they aren’t making 270 right now.  30-06 brass could be used but it is too short for what I want to do.  The necks end up shorter which limits the seating depth range.  With Lapua you don’t have to worry about the primer pockets, flash holes and neck thickness.  The type of deburring tool I like is caliber specific and it won’t cut too deep.  The cheaper ones often keep cutting as you add more pressure.  Flash hole deburring is not something you have to do most of the time but I have never checked Norma brass.

I let the barrel soak over night then ran a wet patch.  I then took a .308″ nylon brush and ran it back and forth 10 times. ( I don’t have a 270 jag or brushes yet)  I am using a 6.5 jag and 308 patches.  I cut a small strip off one of the patches as a backer to make the 308 patch a little tighter.  I then patched it out and took some pictures.  Image 5 is at the start of the rifling.  6 is going down the barrel and is consistent for the first 12″.  But after that there is still some copper.  See pic 7.  Ran a wet patch and will let it soak over night again.

If you don’t have a bore scope buy a Teslong.  It will teach you that a clean patch does not mean you have a clean barrel.  And a lot more. You’d be surprised where you can stick one of these.

https://teslong.com/products/new-rifle-borescope-with-4-5-inch-ips-hd-screen  I have the 26″ rigid but the 45″ flexible may be your choice. It comes with 5 mirrors.

Yesterday I loaded 51 cases with H 4831-SC. The container said 59.5, Hornady manual said 59.9 for max, Sierra manual said 56.2 for max and the Berger manual said 55.7 for max.  Most of these were assuming a 150 gr bullet.  I’m using a 145 gr Hornady so the Hornady info is for this bullet.

So which is correct?  In my experience, none of them.  I picked 56.5 grains.  Well under what Hornady says is max.  My scale can weigh to .02 grains of accuracy.  That means my loads are 1 kernal apart, max. Most manuals use safe numbers.  I read an article years ago about how several manufacturers selected the MAX.  I can’t remember the exact details but none of them want to get sued.  I will find my Max during the powder ladder testing.

I seated the one odd ball case at the longest hard jam number I got.  2.694″ base to ogive.  The rest are seated at 2.671″.  This is minus .020″ from the shortest hard jam I got.  All of these are over the COAL.  COAL is only used for fit in a magazine. These are in the lands but I don’t know how much.  I want the round to be up against the bolt face and the bullet in the lands.  This way the case will stretch where it should. Too much headspace will cause the case to stretch at the .200″ line and possible cause case head separation down the line.  I want this brass to last as long as possible.

The first 5 rounds and the odd ball may have different fps because these had bullets inserted and then removed.  The brass rebound enough to hold the bullets. I haven’t received my neck bushing yet to reset the tension.  So the neck tension will be less.  I’ll shoot the first 5 first to get the barrel up to temp and foul the barrel.  I will shoot the odd ball next.  This case will be the one I drill and thread to check for bullet touch.  Remember, I’m just trying to fire form these cases.  I will shoot at a target and chronograph each shot.  If I can.  Supposed to be very windy and it may blow over the chrono or blow away the target.  

Still soaking the barrel.

Uniformed the primer pockets and got out a lot of brass.  Now each one is the same depth. From now on I will use the uniforming tool to clean the pockets.    Neck sized the cases.  Now that I have the .300″ bushing the necks should have come out at .300″ OD but instead they are .298″?  I then ran the .275″ mandrel in them.  I measured 10 pieces of brass. 6 are .301″ OD and the other 4 are .300″.   After I seat the bullets I will measure them again.  The difference is the neck tension.  I cleaned the brass and will chamfer and de burr the case mouths.

More tools.

Tool with a fire formed case attached for finding where the bullet touches the lands.

Type S bushing die and micrometer seating die.  Notice the expander mandrel and the bushing.  The mandrel goes in a different die. The center shaft of the die has the de capping pin removed and the expander button.

Tool for loading primers into the tubes.

Primer seating tool and the gauge that measures the seating depth.  Seater has .001″ adjustments.  The gauge can measure primer pocket depth and primer thickness too.

The rock chucker has the de capping die, the first co ax has the expander mandrel, the next co ax has the sizing die and finally the MEC is set up with the seating die.