Bullet touching lands reloading question

[earl1704]

22-250 AI new barrell
Reloading for a new barrel, my question is; will the maximum powder load be anywhere near book maximum load with the bullet jammed in?
How to fire form better?

I tried to fire form by following Noslers suggestion for the 22-250 AI as follows;
Loaded a standard 22-250 case with relatively fast powder H4895 31.5 grains (max load would be 33.8 gr. minimum 29.5 gr.) with Hornady 53 gr V-max bullet. Snug the bullet to the lands with the head against the bolt face (eliminating case stretching in the web area). Every case had case head separation with splitting almost all the way around and tight bolt.
The cases used had been fired 3 or 4 time before.
Bought new Winchester brass loaded same as before but pulled the bullet out of the lands, have bright rings at case head area.
Am I fire forming incorrectly?
When I do get a proper fire form with the bullet seated in the lands do I start with minimum loads and will I stay there e.g. nowhere near maximum loads?

Thanks for any thoughts.....................Earl

 

[MudRunner2005]

DO NOT load anything near a max load with the bullets jammed into the lands. That creates pressure-spikes and is asking for trouble.

When forming brass, seat the bullets jammed into the lands that way the case is firmly being held against the lead and against the bolt face. But always run a book starting load. NEVER run more than a book starting load when fire-forming brass. I don't care who tells you that's good practice, but it's not, and it's asking for trouble. The pressure spikes can also crack the necks of your brass and ruin them, which then becomes a complete waste of time, effort, and money.

 

[just country]

morning, LISTEN TO MUDRUNNER. VERY KNOWLEDGEABLE
SHOOTER. justme gbot tum

 

[L.Sherm]

It also helps to anneal your brass before fireforming.

 

[bigedp51]

morning, LISTEN TO MUDRUNNER. VERY KNOWLEDGEABLE
SHOOTER. justme gbot tum

The Sierra website FAQ and manual states the same thing MUDRUNNER2005 said above and it is very good advice. You can also use the false shoulder method with your bullets seated at their normal length without worring about pressure spikes.

 

[Slick8]

MR for the win.

My rifle is set up for heavies so I loaded 69 grain SMK's at .005 into the lands and a starting load of W760 with new Lapua brass.

Here's the results of the case and a 25 shot 3/4 moa group at 100 yards.

 

[Varmint Hunter]

It sounds to me like your chamber is not cut correctly. I'm not a gunsmith but have had a few AI rifles. Normally, an AI chamber will headspace about .002" tight so that the un-formed case fits slightly snug when the bolt is closed. This requires the barrel to be turned in a thread or two before cutting the AI chamber. When cut properly, you shouldn't need to load bullets into the rifling because the case can't move.
However, my practice was to load long (heavy) bullets into the rifling and to use a starting book load with a recommended powder of a medium burn rate.
Occasionally, it would take two firings to get the new shoulder angles sharp.
The case head separation that you are seeing is a reason for concern IMO.

 

[bigedp51]

Varmint Hunter
I have had brand new cases .009 shorter than my GO gauge, Meaning you are at the mercy of the new cases shoulder location as manufactured.

You are correct that they say just fire the standard cartridge in the AI chamber. But manufacturing tolerances can throw this statement to the wind. Most factory cases are at least .002 to .004 shorter than the chamber.

 

[MagnumManiac]

This sounds like an overly long chamber.
I have a few improved chambers including the 22-250AI, if you put a NEW UNFIRED piece of brass in your chamber, you should feel some resistance on bolt close as the handle drops. If you feel NO RESISTANCE on bolt close, then your chamber DOES NOT have the required .005" NEGATIVE HEADSPACE.
The only remedy for this is to use a fast pistol powder, COW (cream of wheat) and a plug of toilet paper and fire form. This allows brass expansion to the chamber WITHOUT any case stretch, then you will have to neck size until cases become difficult to chamber, then partial FL size to just allow easy chambering again.
My first AI rifle, a 257 BobAI, had the same issue, it did not have negative headspace and brass would separate on the first or second firing. When I fireformed with COW, the problem disappeared, but I then pulled the barrel, cut off one thread and re-cut the chamber correctly. I discovered my 'smith used a go-gauge to set headspace, which is wrong on an AI chamber.

Cheers.

 

[L.Sherm]

I got some Rem. 221 fireball brass that was .010 short and 1 case that was .005 to long bolt wouldn't even close.

 

[earl1704]

This sounds like an overly long chamber.
I have a few improved chambers including the 22-250AI, if you put a NEW UNFIRED piece of brass in your chamber, you should feel some resistance on bolt close as the handle drops. If you feel NO RESISTANCE on bolt close, then your chamber DOES NOT have the required .005" NEGATIVE HEADSPACE.
The only remedy for this is to use a fast pistol powder, COW (cream of wheat) and a plug of toilet paper and fire form. This allows brass expansion to the chamber WITHOUT any case stretch, then you will have to neck size until cases become difficult to chamber, then partial FL size to just allow easy chambering again.
My first AI rifle, a 257 BobAI, had the same issue, it did not have negative headspace and brass would separate on the first or second firing. When I fireformed with COW, the problem disappeared, but I then pulled the barrel, cut off one thread and re-cut the chamber correctly. I discovered my 'smith used a go-gauge to set headspace, which is wrong on an AI chamber.

Cheers.

Just so I have this right.........when I put an unfired and UNSIZED case in I should have some resistance ........and I do just a bit tight. But I FL resize my cases before I load them the first time for uniformity after that I do NOT have any resistance. Should I not resize them out of the bag? Just load them?

Thanks for your input..........Earl

 

[bigedp51]

Just so I have this right.........when I put an unfired and UNSIZED case in I should have some resistance ........and I do just a bit tight. But I FL resize my cases before I load them the first time for uniformity after that I do NOT have any resistance. Should I not resize them out of the bag? Just load them?

Thanks for your input..........Earl

You may be bumping the shoulder back when you full length resize the case.

Try putting a .020 to .010 feeler gauge between the die and shell holder. This should still squeeze the case body and size the neck but not touch the case shoulder. Or if you have them Redding competition shell holders will do the same thing as the feeler gauges and not have to adjust the die.

As you can see below you can make a fired case longer than the chamber. "BUT" a new case might not be squeezed enough to make the shoulder move upward in the die. You could try feeler gauges thinner than .010 and see if the shoulder moves.

 

[Varmint Hunter]

I got some Rem. 221 fireball brass that was .010 short and 1 case that was .005 to long bolt wouldn't even close.

That has to be the least consistent brass I've ever heard of. Brass that is .010" short in headspacing is an issue. Brass that has to be crushed .005" in a SAAMI chamber is ridiculous.

It appears to me that the issue the poster has is caused by excessive headspace. But .... like I said, I'm not a gunsmith, just an avid shooter/handloader.

 

[bigedp51]

That has to be the least consistent brass I've ever heard of. Brass that is .010" short in headspacing is an issue. Brass that has to be crushed .005" in a SAAMI chamber is ridiculous.

It appears to me that the issue the poster has is caused by excessive headspace. But .... like I said, I'm not a gunsmith, just an avid shooter/handloader.

I have Lake City 5.56 M193 ammunition that is .003 shorter than my GO gauge.
SAAMI minimum rifle headspace 1.4636
SAAMI max & min case shoulder location 1.4666 to 1.4595 or .007 allowable manufacturing tolerances. Meaning a new case could be .003 longer than the GO gauge or .004 shorter than the GO gauge and still be within manufacturing limits.

And do not forget SAAMI min and max headspace on the average chamber is .010. The GO and NO-GO gauges have .003 between them and are for setting up a new rifle or barrel. And the Field gauge gives you .006 allowable wear or lug setback from the NO-GO gauge.

On a British .303 Enfield rifle at max military headspace with a rim thickness of .058 you will have .016 head clearance. Your head clearance in the chamber is the same as the amount of shoulder bump from sizing.

Pacific Tool and Gauge offers three lengths of headspace gauges per rifle caliber. In order from the shortest to longest, they are: GO, NO-GO, and FIELD:

1. GO: Corresponds to the minimum chamber dimensions. If a rifle closes on a GO gauge, the chamber will accept ammunition that is made to SAAMI's maximum specifications. The GO gauge is essential for checking a newly-reamed chamber in order to ensure a tight, accurate and safe chamber that will accept SAAMI maximum ammo. Although the GO gauge is necessary for a gunsmith or armorer, it usually has fewer applications for the collector or surplus firearms purchaser.
   
   
2. NO-GO: Corresponds to the maximum headspace Forster recommends for gunsmiths chambering new, bolt action rifles. This is NOT a SAAMI-maximum measurement. If a rifle closes on a NO-GO gauge, it may still be within SAAMI specifications or it may have excessive headspace. To determine if there is excessive headspace, the chamber should then be checked with a FIELD gauge. The NO-GO gauge is a valuable tool for checking a newly-reamed chamber in order to ensure a tight and accurate chamber.
   
   
3. FIELD: Corresponds to the longest safe headspace. If a rifle closes on a FIELD gauge, its chamber is dangerously close to, or longer than, SAAMI's specified maximum chamber size. If chamber headspace is excessive, the gun should be taken out of service until it has been inspected and repaired by a competent gunsmith. FIELD gauges are slightly shorter than the SAAMI maximum in order to give a small safety margin.