Tight Chamber

[MrMajestic]

Brass is all new Lapua Brass, never been fired. Length should not be an issue. I don't have a Wilson gauge.

When did Lapua make .270 WSM cases?

 

[onelastshot]

When did Lapua make .270 WSM cases?

I have to correct myself, I mispoke the brass is Norma. Just spoke with the rifle maker. He told me that the issue is using a RCBS dies. He said their specs are all over the place and recommended using Redding. I'm going to purchase a set of Redding dies today.

 

[msinc]

Is it a factory barrel / chamber? I would blacken the case and try to chamber , see the rub marks . I'm still guessing it's a sizing issue , make sure your shell holder is touching the sizing die and cams over , rotate the case 180 and do it again .

This!!! Lets quit guessing and find out exactly what is stopping the cases from chambering properly, then attack that. When Ggmac says to "blacken the case" {there are all kinds of ways to do it} I think one of the best ways is to use a case that is known to stick, smoke it up all over with a candle and very carefully drop it into the bone dry chamber. Hold the rifle vertical {bolt out}, muzzle down and press on the back of the case with your finger or a piece of wood, etc. Turn the rifle up on the butt and tap it loose {cleaning rod} and have a look. This way you are not gunching it all up trying to feed it in with the bolt, which could give you some false marks. You want to see just what is happening in the chamber to the case and nothing else misleading.
Not too many bad dies out there, at least I haven't seen them. There are a few bad chambers, although I don't know how anyone would get one "out of round"???? One thing a lot of guys have trouble with is trying to use brand A shell holders with brand B dies...couple that with a possible brand C press and sometimes you just don't get things to work together. Suggest you get the tooling to measure case length at headspace/shoulder....just about all reloaders can benefit from knowing "before and after" on this dimension.

 

[243winxb]

Just spoke with the rifle maker. He told me that the issue is using a RCBS dies. He said their specs are all over the place

Engineering tolerance: Is the permissible limit or limits of variation in: a physical dimension.

See SAAMI drawings of cartridge and chamber. 270WSM

Maximum loaded round , head to datum- 1.730"

Minimum chamber, head to datum- 1.726"

A minimum chamber may not let the bolt close on a maximum cartridge/loaded round.

https://saami.org

If you reverse the tolerances, the cartridge can have .013" slop to rattle around in the chamber.

When a cartridge runs at an average 65,000 PSI, you dont want slop.

Thinking custom die from 3 fired brass?

.

 

[TikkaSporter]

I have to correct myself, I mispoke the brass is Norma. Just spoke with the rifle maker. He told me that the issue is using a RCBS dies. He said their specs are all over the place and recommended using Redding. I'm going to purchase a set of Redding dies today.

Why not just send some fired brass to Whidden and get a die made to match your chamber verses rolling the dice again with another factory die? Even if your chamber is undersized, a die made for your chamber should be able to resolve the issue.

 

[onelastshot]

Why not just send some fired brass to Whidden and get a die made to match your chamber verses rolling the dice again with another factory die? Even if your chamber is undersized, a die made for your chamber should be able to resolve the issue.

Thanks for the response, I think I'll give Whidden a call. I spoke with the gun smith that made the rifle for me and he said that he makes his rifles with tight chambers.

 

[243winxb]

Contact RCBS. They may tell you to return dies with 3 fired brass from factory ammo.

Does factory ammo chamber?

 

[TikkaSporter]

Thanks for the response, I think I'll give Whidden a call. I spoke with the gun smith that made the rifle for me and he said that he makes his rifles with tight chambers.

Worn and/or dull reamers make 'tight chambers' too. If the reamer started out at a tight chamber spec, it'll cut less chambers before it gets worn and becomes overly tight, leading to issues. After having dealt with a couple TIGHT chambers that were cut with worn reamers that should have been replaced instead of used again, I've decided that a 'tight' chamber spec is over-rated. I remedied one by getting custom dies made for it that fit the chamber spec and sized the brass enough to prevent issues. The other one was fixed by a smith that I trust, carefully putting his 'not tight, SAAMI Spec' reamer into the chamber and spinning it by hand to open up the chamber dimensions slightly. No more problems after he did that and it shot like a dream afterwards.

 

[swd]

I’ve seen a lot more loose dies than tight chambers. Until you measure and compare fired to new brass and sized brass it’s all just a guess...

 

[onelastshot]

Melvin Forbes is known nationally for his product, he's known for designing the ultralight rifle. If he tells me it's a tight chamber, it's a tight chamber.

 

[swd]

Great I’m glad you’ve got it all figured out

 

[sdean]

And after all this see reply #2