A buddy had a .338-06 built after shooting mine and liking it. Win 70 action Lilja bbl,etc

Anyway he has been having problems getting it to group so brought it over yesterday. The fired cases look as though one took the case and sent it into a seat die and added a HEFTY roll crimp! The last .060"-.070" of the neck is crimped in about .010" compared to the rest of the neck. Its noticeable to the naked eye.

His loads are reasonable and the cases don't really show any glaring pressure signs. NOT being the best evaluator of pressures signs I took a pair of twice fired cases and loaded them five times. NO trimming required, primer pockets tight,etc. So I'd think his loads are within reasonable pressure limits.

The rifle shoots MEDIOCRE at best. 2" at 100 yds is about it. What do you think of this??

The Smith that chambered the rifle IS quite competant. Hell he built mine and it shoots and functions 110%.

Could this "taper" affect accuracy and pressure. Seems like it would to me.

FN in MT

Frank, I have seen some reamers like that but they are intended to have a throater to cut the throat. My 9.3X62 and my 9.3X64 is like that, fairly fast taper to the neck of the case.

Is the "crimp" real fast or is it the result of a long sharp taper?

[ 10-12-2003, 22:52: Message edited by: Customstox ]

I'd take it back in a hurry.
If it is as you describe, it sounds like the neck of the chamber is too short, or tapered. Maybe a worn reamer?
It is likely to cause pressure problems, and the safety of firing it should be considered.

Gentleman,

The taper is gradual, BUT surely noticeable. The case necks on My fired cases are straight with NO taper at all. I even loaded up a long case right at the published max OAL and it was still straight.

What should he tell his Smith? The chamber reamer may have been worn and his chamber needs to have the neck taper removed?

This rifle was a real departure for this guy, a normally very conservative guy who buys factory and thats it. I REALLY want to see his gun shoot well and be an enjoyable situation for him.

FN in MT

FN in MT

Time for a chambercast. Can you post a close up of his fired cases?

(The ole light bulb flickered a little)

There is the possibility that when the smith polished the chamber after reaming that he was a bit to aggressivehave & might have gotten into the bottom part of the neck. Just a thought, as this is somthing that I am very concious of when polishing any chamber.

[ 10-12-2003, 23:47: Message edited by: D Humbarger ]

On second thought, I can not imagine that you could even chamber a round in a chamber cut with one of my reamers without it being throated first. How far away is the smith?

Another possibility is he cut the chamber with a 30-06 reamer, and used something else (like a neck/throat reamer) to cut the neck and throat.

A short cut, and a way to avoid spending money on reamers. Bad way to do things.

Not a good way to cut a chamber, as you can see.

Take it back, ask the gun guy if he test fired the rifle, and ask to see the cases from the test fire.

I would not shoot the rifle, as something is wrong. If the neck of the chamber is short, and pinching the case into the bullet, you will have pressure spikes, may rupture a case and have a lot of high pressure hot gas running around in the action and headed towards the eyes of the shooter.

I agree..... a baffling situation. His loads are basically the same I've used and the cases do NOT show any excess pressure signs. Like I mentioned earlier I took a pair of twice fired cases and did one of my 250 grain loads FIVE loads and the cases did not grow more than maybe .005" . And primer pockets were tight from start to finish.

BUT the big deal is the gun is just NOT acurate. All the usual suspects have been eliminated and it SHOULD shoot! So this "crimp" situation has me stumped.

If I can get a digital to show the cases close enough, and in enough detail, I'll post a scan.

My thoughts are to take it back and have the Smith take a look at it. Only 2 weeks to big game opener and this guy wants to use his new rifle.And I feel some responsibility for his angst as I talked him into having the rifle built! So here he is a grand later with a two inch shooter.

FN in MT

Which portion of the neck measures the proper diameter for a fired .338 caliber round? Is the rear portion too large or the forward portion too small? That would make a lot of difference as to performance and pressures.

At any rate, the chamber should not be that way and should be returned to the maker.