450Bushmaster.net

Glad you got your 450 project under way!

Sounds like we have the same barrel, hope yours shoots as well as mine is:)

As the 450 headspaces off the mouth I'm not sure how well the fired case method would work, hopefully some more knowledgeable ppl will chime in.

Not sure what your time line is but I have a "GO" gauge loaned out, if you can wait for it to return you are more than welcome to borrow it.

I plan on sizing a once fired case and have the case trimmed to proper length before using it as the GO gauge. Will recheck head space with a piece of scotch tape on base of case as a NO GO gauge. I'll keep the use of your GO gauge in mine if it take some time for my brass to get here, thanks!

Tom

Sounds great. Why not rent a set of gauges, though?

Got the Savage Axis done! Rhineland barrel was heads paced with a once fired case trimmed to 1.695". A double thickness of Scotch brand tape measured 0.004" and was used as the NO GO gauge. That setup allowed the bolt handle to move only about a half inch before it stopped so I think I'm good to go. Got a little creative loading some test rounds. I have the Bushmaster size die but had to use a combination or 45 ACP and 45 Colt dies to assemble the rounds. Test loads are with 250 gr RNFPs that are plated bullets. Their loaded over 29.4 grains of 296 and OAL came out to 2.102". Load will be lit by Wolf magnum Small rifle primers. I'll be trying it out this morning for the first time.

Tbk wrote:Sounds great. Why not rent a set of gauges, though?

Tried to get one on line either buying or renting and no one had any. PTG said it was going to take 6-8 weeks to fill my order. Clymer didn't list one.

Good luck! Be sure to let us know how it shoots.

I've set headspace like that before with no issues.

But Dave Manson usually has gauges in stock.

07Kingpin wrote:Good luck! Be sure to let us know how it shoots.

Just got home from shooting the new build. Fired just fine. 29.4 grains of 296 was a bit weak. Velocity was all over the place with an ES of 122 and averaged 1507 fps with the plated 250 gr RNFP. I believe my taper crimp was too light, unburned powder in the barrel. At least I have it sighted in at 100 yards now and can really begin load development. All of my older manuals have no Bushmaster data. My latest Hornady manual is the only one that has data for the Bushmaster but it's all jacketed bullets. I'll have to search the web to find cast gas check load recipes.

Searched and searched, no useful data on the internet for heavy cast bullet loading in the Bushmaster, everything is jacketed. I just ordered the 50th Edition of the Lyman manual from Amazon, hope it has some decent cast data.

GaCop wrote:Searched and searched, no useful data on the internet for heavy cast bullet loading in the Bushmaster, everything is jacketed. I just ordered the 50th Edition of the Lyman manual from Amazon, hope it has some decent cast data.

A snapshot from 9 years ago:

http://450bushmaster.net/viewtopic.php?f=5&t=5252&start=10

Lots more experimentation chronicled here over the years and if it comes from member "pitted bore" you can take it as gospel. Lots more reading using the Google forum search tool site:450bushmaster.net boolits.

Search process detailed in my post in Hoots Information Depository sub-forum here:
http://450bushmaster.net/viewtopic.php?f=15&t=15629

Keep your search term(s) as simple as possible.

BTW, I also work for LEO, albeit for a short while longer. Just about to retire after 23 1/2 years.

Hoot