My first custom chamber: 300 Ultra X! (Creedmoor was taken)

[SENAL]

I get bored
Trying to figure out the kinks will take you guys when I get that far. Looking forward to the guys that use this method for some really cool stuff that I'm not smart enough to figure out.

well I hope this shows as another great lesson to others that mainstream is blah. Custom chambering and making your own stuff can be doable and extremely rewarding. Nothing like squeezing the trigger on something you created.

Furthermore, standardizing it for you, your friends isn't all that hard either. Reamers,dies, brass(cnc, not cheap but it's worth it at that point).

 

[Mram10us]

well I hope this shows as another great lesson to others that mainstream is blah. Custom chambering and making your own stuff can be doable and extremely rewarding. Nothing like squeezing the trigger on something you created.

Furthermore, standardizing it for you, your friends isn't all that hard either. Reamers,dies, brass(cnc, not cheap but it's worth it at that point).

I like that this method is free. I already had the reamer, brass and dies, so add in a bit of patience and we might have something

 

[MNbogboy]

Sorry, just realized I never responded. Case head seems to be normal, primer pockets didn't loosen at all. I really think the pressure signs are false due to the flat, based on primers not flattening and speeds.

Ah, but you did in post #49...

Think that your chamber polishing may allow brass to extract easier especially through the flat section. The headspace reduction may help also by holding the case head closer to the bolt face. Hopefully reducing case stretch. The ejector marks and the even the case separation possibly are a result of "delayed" slamming of the case backwards do to the original "finish" of the straight section. The polishing in that area may help.
Good luck on today's shoot,
Randy

 

[Mram10us]

Ah, but you did in post #49...

Think that your chamber polishing may allow brass to extract easier especially through the flat section. The headspace reduction may help also by holding the case head closer to the bolt face. Hopefully reducing case stretch. The ejector marks and the even the case separation possibly are a result of "delayed" slamming of the case backwards do to the original "finish" of the straight section. The polishing in that area may help.
Good luck on today's shoot,
Randy

Gotta work today, but when winds die down at home, I'll head out to the range. Still have a couple hours on the lathe polishing more and reducing headspace. Hard not to enjoy this stuff
Guess I should re read and pay better attention I don't feel so bad now

 

[MNbogboy]

Gotta work today, but when winds die down at home, I'll head out to the range. Still have a couple hours on the lathe polishing more and reducing headspace. Hard not to enjoy this stuff
Guess I should re read and pay better attention I don't feel so bad now

+15F here today with snow first & more below zero to follow....I had some more seating tests loaded last week, so took advantage of this short break.....my .009 test today matched a .010 test on Jan 2, so fine tuning from .009/.010.

 

[Mram10us]

Took out the ultra X for the final time today. Here are the final findings:
1. It seems the flat in the chamber from the beginning of the chamber forward .700"ish is too much. It makes chambering tighter than it should be
2. After firing 5 times for each case, the case needed to be sized to the base. The 300wsm FL die wasnt Long enough
3. The growth on the sides of case was too much for Rem brass, but Norma and Bertram did well.
4. Accuracy was great. Very happy there
5. Learned a bunch about alternative fireforming methods, so that a plus
Next tests will be on chambering with cases that have less case growth on sides and less flat near the base

 

[birdiemc]

Took out the ultra X for the final time today. Here are the final findings:
1. It seems the flat in the chamber from the beginning of the chamber forward .700"ish is too much. It makes chambering tighter than it should be
2. After firing 5 times for each case, the case needed to be sized to the base. The 300wsm FL die wasnt Long enough
3. The growth on the sides of case was too much for Rem brass, but Norma and Bertram did well.
4. Accuracy was great. Very happy there
5. Learned a bunch about alternative fireforming methods, so that a plus
Next tests will be on chambering with cases that have less case growth on sides and less flat near the base

Funny you dragged up this thread I just mentioned our datum dimension discussion in the other discussion we're having lol

 

[birdiemc]

Took out the ultra X for the final time today. Here are the final findings:
1. It seems the flat in the chamber from the beginning of the chamber forward .700"ish is too much. It makes chambering tighter than it should be
2. After firing 5 times for each case, the case needed to be sized to the base. The 300wsm FL die wasnt Long enough
3. The growth on the sides of case was too much for Rem brass, but Norma and Bertram did well.
4. Accuracy was great. Very happy there
5. Learned a bunch about alternative fireforming methods, so that a plus
Next tests will be on chambering with cases that have less case growth on sides and less flat near the base

It's a shame you cant put metal back after you ream it out

 

[MNbogboy]

My guess is several people learned some real valuable things from your venture including myself.
You will be able to rechamber that barrel knowing it shoots great.
Thanks for starting this thread and walking us through it all. We all can guess about things but we will never know until we try.
Randy

 

[Mram10us]

Hope it helped. I have enough shank left to re chamber. Just need to figure what's next Learned a lot.

 

[Mram10us]

It's a shame you cant put metal back after you ream it out

Really??? There has to be a way

 

[sturner]

Oh I'm definitely tagging in on this

 

[sturner]

deleted

 

[birdiemc]

Well there's ways...just not recommended