Boats, just for a reference, here's what I use in my Borchardt with the 100 Nosler BT. 41 grains of IMR 4350 for 2832 fps or 41 grains of H414 for 2984 fps. Never played with lighter bullets as I intended to use it for antelope.

One at a Time

Gave the Internet one more try, instead of looking at my usual suppliers just looked for power for sale by name.

Never knew Brownells sold powder.  Out of almost everything. Had 3 lbs of H414. Looked in "propellant profiles" it's burn rate is just a bit slower than 4350 and being a spherical powder ought to measure.  3 lbs 200 Sierra 117 flat base 200 Sierra 117 boat tails am in business.

Fire forming loads 87 gr bullets bench rest, 12 lb CPA Unertl 10x it's ridiculously easy to hit our club steel swingers at Silhouette distances. Windy day to did some holding off.   200 300 385 Meters. I have no plans to shoot game at 385 but nice to know it will hit center at distance. 

Boats

Here are a couple of photos, big departure from my other CPA's  It's going to spend most of it's time BPCS with the 40/65 barrel. One or two Deer and Varmint Hunts a year with the .25 Krag  

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Chamber cast, formed, fire formed & loaded. 3 bullets 87 & 2 117's

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Have to figure out that beavertail forearm.  Some look nice most not so nice. It is a good handle. Been on the bench to get loads and sight's once set it will only be shot off X Sticks or that  Protekor Window Bag.  Handy you can throw them over anything & get a consistent uniform rest.

Boats

Guess I knew that but did not think of it.  Was surprised by the pressure first full power loads. Now that a proper powder is on the way will pay more  Attention to the seating depth and back off just a bit on O/L length.  

Idea is to get a standard dimension for all 3 possible bullets. I dropped all 3 in a Drill Gauge hole miked the protrusion and seems all the Sierras have the same nose shape. Heavy longer than the lighter ones on the base end.

Frank sent me a nice supply of brass. Some with interesting Head stamps.  .30 USA .30 Army .30 Gvt.
Be good way to keep the different bullet cartridges separate

Boats

Back at the Range this week with fire formed cases proper slower powder, H 414, and 117 gr Boat Tails. Primed cases threw the charges and seated bullets on the firing line moving up charges half a grain at a time.

Getting more pressure than I should with lighter loads than 250/3000 data. Primers are starting to flatten at 29 grs 250/3000 data smaller case capacity shows 34 grs as starting with the same bullet

When forming cases outside neck turned just a bit, to even things up.  Cutter took off half a turn of brass down some from the mouth. cut whole turns near the shoulder. Very little material taken off.

Back home I miked a dummy round loaded O/D .287. Fired Case is also .287 .  My Cerrosafe cast shows .290 should be plenty of clearance however the rifle chambers and extracts hard.

Friend of mine with more experience in High power wildcats than me said the fired case neck needs a bit more expand and spring back, should end up .001 or ever .002 larger-after it's been fired than a loaded round. Tight neck causes more pressure.

Am going to turn a bit more off the neck wall thickness see what happens. 

Any opinions  or other ideas ?

Boats

Frank, 

Will mike further down the case compare fired with sized and let you know. Also polish the necks and mark up to witness hangs.

Those cases you sent me ? I separated dozen of the .30 USA head stamp to try.  Out of the F/L sizer die they would not chamber hanging about 1/2 up from the rim. With the CPA barrel off they would chamber when tapped with a wood mallet, had to be lightly tapped out with the cleaning rod. Miked they were just a bit fatter than the new WW cases.  Made a mandrill chucked up 3 of them in the lathe and relived the case about .002  bottom half inch and they chambered just fine. Very little material taken off, Some fine paper no way to even tell they have been turned. Did not have any sticky chamber or extraction problems when running fire form loads in the turned .30 USA. Be interesting to see  how they do with full power loads.

What with the reamer from one supplier sizing die from another no rule things have to work like a factory round.  Get the cases right normal practice  with a bolt action is case body needs no further attention. Perhaps not so with a weak extracting single shot.  CPA crams one in easy extraction is another matter not as strong as a bolt rifle. When I say sticky you can open with the leaver and extract it's just harder than you would expect.

Boats

You should be able to use, at least starting loads for the 257 Roberts. I have New 257 Roberts cases. I'll measure the water capacity in grains  to the top of the case and you measure some of your FL sized cases.

I believe that is the best way to decide how close to Roberts loads that you can use.

Frank

Mike 

I tried that dodge the quick and dirty way. Pushed the case all the way up in the die with a washer over top of the shell holder. It did size the "fat" case down to fit but still a little tight. About the same effect as taping one in the CPA barrel with a wood mallet.  Base thickness only cases that were tight are the .30 USA


Boats