Gunsmithing 338 edge chamber problem

[ar15is223]

Hello I just finished this build. I started with a remington 700 action I then trued it. Then I installed a shillen barrel on it that I also threaded and chambered myself. One of the first problems I realized that I had is that my neck is to tight. The reamer I orderd cut a .369" neck diameter, while the loaded cartriges have a .367/8" neck diameter. I dont want to neck turn so I guess I will order a neck reamer in a larger diameter. The next problem I have is that some of the loaded rounds are hard to chamber. I can get the bolt closed but then after opening it and pulling the cartrige out there is gouge on the bullet about 1/16" fron the top of the neck and about 1/4" long. I just cant figure out what is causing this mark on the bullets. My guess is that the throat might be too short, but im not sure how to check that. I included a picture of the cartriges with the gouge. Im trying to fix this without pulling the barrel because I already bedded the stock. I am using 338 ultra reloading dies to load a 300 grain SMK into a remington case if that helps. Thank Nick.

 

[ar15is223]

Re: 338 edge chamber problem

Update:
I decided to pull the barrel and run the finishing reamer back in the chamber by hand to see if there was a burr at the neck area of the chamber. That did not fix the tight neck issue or the gouge on the bullet. I am sure that the tight neck is what is causing some of my problens, but the marks on the bullets is what I cant figure out. Thanks, Nick

 

[Sportin Wood]

Re: 338 edge chamber problem

Have you measured the COAL of the load after you chamber it? Is it any different from your loads that you haven't chambered yet?

 

[Glen Seekins]

Re: 338 edge chamber problem

Just curious, how does a piece of brass chamber without a bullet?

On the top case in your picture it looks like there is a slight bulge where the case body transitions to the shoulder. Maybe its your picture? I have seen this when necking up or down cases. maybe its just your picture but the light shows it very well. This will make it difficult to chamber just the last little ways before the bolt closes. It wont shoot worth crap either. Most likely your necks are no longer straight with the rest of the case if this isn't a optical illusion. Easily fixed when you fire form the brass the first time.

If your chamber truly measures .369 and your cases are .367-.368 then you should have clearance if i do my math correctly. When i turn necks i shoot for .002 total diameter difference.
I do see a burr on the outside of your case mouth...

Case prep is everything. Make sure its perfect and if you are still having issues there are allot of variables that we probably wont be able to fix via net.

The gouge you see on your bullet are the lands and grooves of your barrel. you most likely do not have enough throat in your chamber. Your chamber print will tell you what it is. Call the place you got the reamer from and ask them what you should have for the bullet you are using. Also let them know if you are restrained for mag box length. Its ideal to have the bullet seated out a ways, but your magazine over all length may not allow it.

edit to add..

Just seen the mark on your bullets in the picture. Either your brass is crooked or something else is. Might be your chamber. You may need a bore scope. Is that mark all the way around or just in one spot? If it is all the way around your freebore diameter may be too tight.

 

[ar15is223]

Re: 338 edge chamber problem

Stanwood: the COAL decreases on the loads that have the mark on them. The ammount varies from cartrige to cartrige but is sometimes over .10 of an inch.

Heatseekins: After reading your reply I realized that some of the loads did chamber without dificulty and others had some dificulty chambering. The one with the gouge on the bullet were the ones that were dificult to chamber, and even when indexed differently into the chamber the mark on the bullet did not move. I don't have a concentricity gauge so I rolled some of the of the cartriges over a flat surface and the ones that were dificult to chamber had their bullets very unconcentric. I've been reloading for several years and have never seen any thing that out of center. Loading for the 338 edge is the first time I have ever used dies for a cartrige they were not origionaly designed for. I'm not quite sure how to correct this issue. I guess I need to figure out if the concenctricity issue is occuring when I expand the neck or when I seat the bullet. I think I might get a set of dies from defensive edge to see if that corrects this problem.

Thank you both for your replies. I will post pictures of the rifle when it is finished. Lol I saw those burs too but the debuting tool I have would not reach it I guess it's time to upgrade to a new debuting tool. This gun / machining hobby is a huge money pit there's always something new to buy.....

 

[Jim See]

Re: 338 edge chamber problem

check your neck wall thickness on the loads that rubbed the bullet, with the tight neck and a thickness of the neck wall that varies .002-.003" you might have the bullet out of center which causes the rub when the bullet enters the lead dia.

 

[Sportin Wood]

Re: 338 edge chamber problem

What dies are you using. Are you using the Defensive Edge 338 Edge dies?

 

[jrpilot]

Re: 338 edge chamber problem

<div class="ubbcode-block"><div class="ubbcode-header">Originally Posted By: StanwoodSpartan</div><div class="ubbcode-body">What dies are you using. Are you using the Defensive Edge 338 Edge dies? </div></div>

I think he is using 338 RUM dies.

Im using RUM dies in mine, and they are working great.

 

[krlemas]

Re: 338 edge chamber problem

I think I would turn the necks on the brass so you have a .002-.003 clearance instead of changing chamber neck.

 

[HarryCallahan]

Re: 338 edge chamber problem

Can we get pics of the reamer? The gouge on the bullets look like the reamer isn't throated and the chamber still needs to have the throat cut in a separate operation.

 

[Skunce]

Re: 338 edge chamber problem

I had the same problem with one of my rifles a 7mm SAUM. Some of the rounds would chamber hard and when extracted would show a scrape mark on the bullet. The problem was too much run-out caused by my resizing die. I sent the die back to the factory and had them hone the neck out from .307" to .313". Fired cases would measure very low run-out, but after resizing I would measure as much as .007" run-out. After having the die reworked and refireforming my brass to straighten the neck my loaded runs have very low run-out and don't scrape the bullets anymore. The accuracy improved a bunch also. I also bought a VLD type seating stem. Your probably getting the excessive run-out when necking up your brass. I'd turn off .002" the case necks and fire form the brass and recheck the run-out.