shoulder bump question (insight needed)

[DJ 480]

ok fellas,
This is a new one for me and I am seeking some sage-like wisdom. I threw a new 308 barrel on my Origin (Bisley chamber). I had some 1x fired brass from my old barrel so I took an OAL measurement (2.2490) and subtracted .020 (seating depth) and figured I would start load dev at 2.229. After the ladder was all loaded up, I threw one in the chamber just to check cycle, and wouldn't you know I got a hard bolt close (and on the rest I checked). I was like WTF no way I am in the lands! So I drew some sharpie all around the ogive and put it back in the chamber to check....no marks. Then it hit me! maybe the shoulder was too long as they have not been formed to this chamber. so I checked all my match 308 ammo I have from the last barrel. all the ones that read around 1.626 on the shoulder bump gauge are hard to close. So I am guessing that the shoulders are just not far enough back on this brass for the new chamber.

now the question, besides hard bolt closures any other issues (pressure related?) would be derived from shooting this? I am guessing not and was just gonna use these rounds as a fire-form opportunity.

Thanks

 

[918v]

You’re supposed to bump .002” not .020”

 

[spife7980]

You’re supposed to bump .002” not .020”

He’s talking bullet seating in that part

If you can chamber them then go for it. I was false shouldering my dasher and with jammed too much it hurts your hand chambering the 50th round super toughly.

 

[DJ 480]

He’s talking bullet seating in that part

If you can chamber them then go for it. I was false shouldering my dasher and with jammed too much it hurts your hand chambering the 50th round super toughly.

Thanks I appreciate it!

 

[spife7980]

Thanks I appreciate it!

Just make sure you inspect it to ensure it’s not too hot in the new barrel before you squeeze shitloads off tempting fate

 

[Steel head]

 

[jakelly]

Be careful not to gall the backside of your bolt lugs.

 

[Criver600]

now the question, besides hard bolt closures any other issues (pressure related?) would be derived from shooting this? I am guessing not and was just gonna use these rounds as a fire-form opportunity.

Pull the bullets dump the powder, size your brass so you can run the bolt with one finger, get it right and move on. You can and will gall your bolt lugs, plus how are you going to shoot groups beating on the bolt.....

 

[supercorndogs]

With a bushing die, you can remove the neck bushing and decapping assembly and size loaded ammo. Make sure its a shoulder bump issue and not a body diameter issue before you get your whole next batch done. I did it with a 20 practical, and ended needing a small base to die make them fit.

 

[DJ 480]

With a bushing die, you can remove the neck bushing and decapping assembly and size loaded ammo. Make sure its a shoulder bump issue and not a body diameter issue before you get your whole next batch done. I did it with a 20 practical, and ended needing a small base to die make them fit.

I might try that on a couple see if it works!

 

[jakelly]

It works.

 

[DJ 480]

Update
Took my rounds that measured 1.6270 on the shoulder bump gauge. Brought them back to 1.6220 and the bolt drops fine.
Thanks for the info guys