300NMM Bushing size???

[Stevo3556]

I would like to order my reloading bushing for the 300NM before I actually have the bullets and cases to measure the OD of the case neck. New caliber for me so the components are on their way.

Does anyone know what their bushing is or the OD of the loaded case neck with Peterson brass and the Berger 230 bullet?

Thank you,
Steve

 

[Milo 2.5]

.336" worked best on a couple of rifles I had my hands on using Norma brass.YMMV

 

[Stevo3556]

Thank you Milo.

Gives me a place to start. I think I have heard the Peterson brass was thicker. Hope to hear from a Peterson brass user.

Thank you for taking the time to help me out Milo.

Steve

 

[Milo 2.5]

Thank you Milo.

Gives me a place to start. I think I have heard the Peterson brass was thicker. Hope to hear from a Peterson brass user.

Thank you for taking the time to help me out Milo.

Steve

Crap, I missed the part where you said Peterson was your choice, sorry

 

[Stevo3556]

No, thank you for taking the time to answer. So now I know it will be close to that and if I don't get a reply from someone with Peterson brass I can order a few in that range. It is the best answer so far!

Thanks,
Steve

 

[Milo 2.5]

I don't know if I can help, but when I have a new to me rifle built, I will have the components in hand so I can get a measurement. It would be very rare I would buy the bushing size that gives me .002" measured tension, I start .003 under. My reasoning is, brass necks stretch on firing, why we trim. I have brought more loads in by adding tension and not going the other way.
Truthfully, you can start loading cases for this gun and buy bushings off your results with new brass. If your load is spot on with new brass, duplicating it is now your goal, and once again for me it is going .003" under new brass loaded rds.
I remember when 6.5 creed was beginning it's rage, a .290 bushing was standard, I do not know anyone personally who used one, they may have owned one though. But then again, maybe they were following my advice ????

 

[Stevo3556]

I received an answer of .336 with Peterson brass which gives him a couple thousandths of neck tension.

If anyone is using something different I would like to hear what you are using.

Thank you!
Steve

 

[Stevo3556]

Milo,

Thank makes perfect sense, but never have heard of that. OK that helps a bunch I will give that a try. I would like to be sent up to load for the new rifle which has been delayed a day. All the components just arrived... Sounds like I will buy a few and while working up the load try different ones.

thank you very much.

Steve

 

[Stevo3556]

So I can also measure with the new components that just arrived. Appreciate learning about actually starting under sized for the measurement on new brass.

 

[Milo 2.5]

So I can also measure with the new components that just arrived. Appreciate learning about actually starting under sized for the measurement on new brass.

Like I said earlier, your mileage may vary, I'd chamfer some new brass and fire it. Go from there, being a 300 Norma, I doubt he is putting over 200 pcs into service, you may end up being into 125 pcs before you have a dedicated load. just not sure how much leeway you have starting out, but new Peterson brass in other cases seems to be heavy on seating force needed.

 

[Precision Underground]

No, thank you for taking the time to answer. So now I know it will be close to that and if I don't get a reply from someone with Peterson brass I can order a few in that range. It is the best answer so far!

Thanks,
Steve

I think mine is a .338 with Peterson. .336 gave me too much tension. I think I am at 1.5 with the bigger bushing. This is from memory but I think that is right.

 

[Stevo3556]

Thank you jpgolffl!

Just ordered one that size as well with your suggestion. Can't beat less than $9 shipped by Saturday.

Steve

 

[Stevo3556]

Loaded new brass last night and unfired Peterson brass neck OD was .338.

Will see how that works IF my rifle makes it here. Was shipped 2nd day air Monday. Was still in CO. early this AM.

 

[Precision Underground]

Loaded new brass last night and unfired Peterson brass neck OD was .338.

Will see how that works IF my rifle makes it here. Was shipped 2nd day air Monday. Was still in CO. early this AM.

Check the headspace if your brass before and after firing. Mine grew almost .020. I was worried my chamber was off but it sounds like Norma, or Norma Peterson brass may just be slightly undersized from the factory. I annealed after the first firing to make sure the grow didn’t harden the brass and it has done well. I have pushed them pretty hard and everything is still tight after 3 firings.