Tight Chamber need to change my Reload setup

[pmclaine]

I recently had a new rifle built.

30-06 Pre 64 Model 70 Winchester with a Douglas barrel blank fit up. The chamber is match cut to SAAMI minimums.

I had sent the builder 4-5 of my reloads when he was cutting the chamber to check things out.

With his typical match chamber my rounds wont chamber. They feed in than you rotate the bolt down to about 90 degrees and it stops.

His factory ammo on hand chambered.

I reload 30-06 for Garands and 03s so Im assuming my war veteran 70 year old guns have loose chambers. I opted to leave the chamber closing on a match gage and I would adjust my sizing die.

When I received the rifle I made my first range trip using factory Federal Fusion 150 grain hunting ammo. Checks with my reloads confirmed they will not chamber but the Fusion chambered/fired/extracted fine.

When I had my sights on target I tried using some Creedmoor sports 167 Lapua scenars in Lapua brass. These rounds were very accurate, They chambered and fired fine but I could not extract them. The bolt turned open 90 degrees than I had to smack the bolt the rest of the way to get extraction/ejection.

This is premium match ammo and I require it to run in this rifle. Gun went back to builder to check things out.

I load on a Dillon S1050.

The builder is finding that my brass is "bowing" just ahead of the bottom of the case.

He had applied some blue dykem to show the contact on one of my rounds....

He also conducted this excellent analysis sheet of some various ammo I sent him to function check in the rifle. Note the Lapuas are not reloads they are factory manufactured with new components at Creedmoor Sports, purchased from the CMP....

My ammo doesnt look that out of whack except for just above the case head section H...

Im wondering if the aid to progressive loading Dillon includes in its die design might be the issue?

I think I may of actually set my dies up using the Creedmoor ammo as it has such a great reputation.

Thinking of running a Redding FL size die after my Dillon trim die to work the bottom of the case.

@padom you are a Dillon man any ideas?

My reloads drop fine into a Dillon case gauge.

Kind of perplexed.

Dont want to give my new rifle a 70 year old chamber in order to use my reloads.

Builder has been great working with also.

 

[RTH1800]

I think you are seeing slight case head expansion in your Garand rifles that is not compatible with your tight chamber '70.
If you can live with using only dedicated brass in that chamber it should be fine. Otherwise a small base die may be in your near future. Redding can make one up for you. Not real expensive. 75-100?

 

[Brandon05_88]

I had a similar issue except it was with prepped brass.
I swapped from a factory AI .308 barrel to an AINA .308 barrel. Lapua brass 1 or 2x fired, FL sized in Redding dies with 0.001" shoulder bump.
New Lapua brass would drop in freely, but fired and prepped Lapua brass would hang up.
I sanded a fired/prepped piece down along the side, attempted to chamber, extracted, and there was a very faint ring all around the case about 1/4" up from the head.
This was about 0.001" too large in diameter from the best I could measure.
I did a good bit of reading, contemplated a new small base die, and finally decided to just run new brass and my regular Redding FL die.

Now what makes all this interesting is that I never adjusted my Redding FL die, and starting with the new brass, and sizing with the same die at the same setting, I never had an issue.
It was only the brass from a different barrel.

I truly think it is from the brass in the looser chamber, the sizing die sizing normally, but something about the elasticity of the brass.
I'd say you may be able to run those loaded rounds into say a small base body die provided the bullets clear.

In the end, new barrel = new brass.

 

[pmclaine]

I think you are seeing slight case head expansion in your Garand rifles that is not compatible with your tight chamber '70.
If you can live with using only dedicated brass in that chamber it should be fine. Otherwise a small base die may be in your near future. Redding can make one up for you. Not real expensive. 75-100?

Thanks for checking this post out.

That particular piece of brass I sent him is on its 4th loading, nothing hot - 46 grains 4064 and a 168, but if its a big chamber and a Dillon die cut like a magwell it might be the issue. Ill be sectioning one to look for casehead separation or thinning.

In the future my size die is going to be set up specifically for the Model 70 and the milsurps will use what is produced for it. I will be getting a few more boxes of Lapua brass to dedicate to the 70 but I also expect to use the other ammo on occasion.

Kind of surprised because the Dillon trim die is cut pretty tight, some say it is a small base die.

Thinking a Redding FL die after the Dillon trim die, will iron out that slight blowout. Ill probably set the trim die to size .001-.002 over SAAMI than use the Redding to get to 0 SAAMI or -.001.

That would solve my reload issue. Dont know why the Creedmoor ammo wouldnt work though.

He opened the chamber a slight amount. Ive asked him to fore one of the Lapua rounds and look for good extraction/ejection.

If he doesnt have to palm the case from the chamber the slight relief may have fixed the issue.

 

[pmclaine]

I had a similar issue except it was with prepped brass.
I swapped from a factory AI .308 barrel to an AINA .308 barrel. Lapua brass 1 or 2x fired, FL sized in Redding dies with 0.001" shoulder bump.
New Lapua brass would drop in freely, but fired and prepped Lapua brass would hang up.
I sanded a fired/prepped piece down along the side, attempted to chamber, extracted, and there was a very faint ring all around the case about 1/4" up from the head.
This was about 0.001" too large in diameter from the best I could measure.
I did a good bit of reading, contemplated a new small base die, and finally decided to just run new brass and my regular Redding FL die.

Now what makes all this interesting is that I never adjusted my Redding FL die, and starting with the new brass, and sizing with the same die at the same setting, I never had an issue.
It was only the brass from a different barrel.

I truly think it is from the brass in the looser chamber, the sizing die sizing normally, but something about the elasticity of the brass.
I'd say you may be able to run those loaded rounds into say a small base body die provided the bullets clear.

In the end, new barrel = new brass.

I was ready to concede my current reloads had a sizing issue.

Whats weird is that the Lapua cases that feed and fire but wont extract/eject are brand factory new.

My reloads wont chamber, factory new lapua wont extract/eject. Run of the mill hunting ammo does it all except give me sub MOA groups.

Fed Fusion 150 with iron sights 10 rounds

7 Rounds of Lapua 167, I only fired 7 because I got tired of struggling to extract....

Gun porn

 

[Brandon05_88]

I was ready to concede my current reloads had a sizing issue.

Whats weird is that the Lapua cases that feed and fire but wont extract/eject are brand factory new.

My reloads wont chamber, factory new lapua wont extract/eject. Run of the mill hunting ammo does it all except give me sub MOA groups.

Fed Fusion 150 with iron sights 10 rounds

What is the chamber neck diameter?
That's the only thing I can think of.
Then again, Federal necks are usually as thick as Lapua.

 

[Sheldon N]

In addition to calipers, get yourself an inexpensive vernier micrometer. You can use it to measure the base of fired and sized cases just above the rim and it will give you more accuracte measurements down to the 1/10,000 of an inch, which actually matters when you are talking about base sizing at the 0.200" line above the case head.

Measure the base of fired brass from the Garand, measure the base of fired brass from your new rifle (both Lapua and hunting ammo) and also measure what each comes out of the sizing die at after having been fired in either rifle. This will let you know if you're getting adequate sizing and if you have sufficient clearance (also looking at neck OD, headspace, shoulder diameter, etc).

I like to have 0.0006 to 0.0015 base clearance after sizing. As said above, if you aren't getting this with your current die then you may need to look into a small base die.

 

[pmclaine]

Why wouldnt the Dillon case gage pick up these issues?

 

[RTH1800]

Phil,

Like most things tolerances and specs vary on case gauges. Our ability to do repeatable, precision CNC work has reduced tolerences but they still exist. In old times this was dealt with by simply opening up chambers etc. Less precision but more interchangeability. Now we have uniform, round min spec bolt gun chambers and try to shoot ammo fired in a 70 year old M1 that has seen 3 wars and lots of rounds down the tube. Does not always work.

I would suggest you use adequate lube, safety glasses and hearing protection if you are to size loaded ammo. I do it and have never had a problem. I do still take precautions.

 

[pmclaine]

Ill not size the loaded ammo. Ive lost about a third of a magazine of primers in the Dillon and that was shocking enough.

Thats going to be mil surp only ammo.

Ill buy a box or two more of the CMP Lapua ammo to dedicate to the M70 until I reload foor 30-06 again.

 

[padom]

Get new brass dedicated for your new match chamber. Fire them in your new rifle. Get a 21st Century turning arbor and put it after your Full Length Dillon Size/Trim die. Setup the trim die to bump the shoulder whatever you want (.001-.003) then right after the size/trim die have the brass run into the expander to set .002 neck tension. I use 21st Century TiN Turning mandrels as they set exactly .002 neck tension. This is how I size ALL my brass for all rifles, gassers and precision bolt guns.

I use the Turning as it gives .002, the expander will only give .001 neck tension.

http://www.xxicsi.com/arbors-and-mandrels.html

 

[Nodakplowboy]

^^^^Will the 21st Century mandrels fit in a Sinclair expander die body?

 

[padom]

^^^^Will the 21st Century mandrels fit in a Sinclair expander die body?

No idea. But we arent talking big money for the body

 

[Nodakplowboy]

True. Thanks for the response.

 

[spife7980]

They should. The mandrels themselves are identical.

 

[DrewC]

Yes they do

 

[Nodakplowboy]

Thank you all, just placed an order.