7mm Benchrest Cast Data

[Kent Fowler]

Was wondering if anyone could point me towards any cast data for this caliber. All I've been able to find so far is what little is on Load Data, which shows 2 discontinued and two current powders and the Accurate manual which only shows AA-5744. One would think there would be more data than what I'm able to glean over the internet. All the silhouette sites seem to be pretty closed mouthed about any loading data, also. Any help would be appreciated.

[JSH]

Kent, I have used FLGC data with fair to good results. I used a start load minus 5%.
A gent gave me some input on SR4759, no luck to my suprise.
jeff

[madsenshooter]

I found some data for the 7-30 Waters and 138gr cast bullets on AmmoGuide. There's a 10% difference in case capacity, so you may be able to reduce these loads 10% to start, and work up from there.

138 Cast RCBS Alliant/Herc Unique
8.5gr
1435


138 Cast RCBS Hodgdon Universal
8.5gr
1446fps

138 Cast Lyman Hodgdon Universal
10.0gr
1586fps


138 Cast Lyman Accurate AA-5744
20.0gr
2010fps

138 Cast Lyman Alliant/Herc Reloder-7
22.0gr
2123fps

138 Cast Lyman Hodgdon H-380
30.0
2129fps


138 Cast Lyman Accurate AA-2200
26.0gr
2191fps


138 Cast Lyman Winchester 748
31.0gr
2247fps

138 Cast Lyman Alliant/Herc Reloder-10x
29.0gr
2355fps

I don't think you'd be likely to get into any pressure problems doing so, you didn't mention what weight bullet you were planning on using. I've used a little algebra to extrapolate loads from one cartridge to another and it has worked pretty good for me. Taking the load that's in view x/40(H2o capacity of 7mmBR)=29/44.7(h20 capacity of Waters) x=25.9grs of Reloder 10x to give you approx the same performance from your 7mmBR. A graphing calculator makes finding the value of x easy.

[BerdanIII]

There might be some data in old issues of The Fouling Shot; I'll take a look.

Do you want BR or TCU data, or both?

[Wayne S]

Have you tried Speciality Pistols.com ?? there should be loads of data already posted, there is also a cast bullet section you can ask.
The general 7 BR load is the RCBS 145 over 15 to 18 gn's of SR4759
The RCBS cast bullet manual # 1 in MHO didn't try very hard to taylor powders to cast bullets, they list ;
25-27 4895

23-25 H322

20.5- 22.5 RL-7

[BerdanIII]

From: Cast Bullet Coefficients - 7mm BR Remington; The Fouling Shot 115-10
Remington XP-100
Lyman 287641 (157 gr) - 24.5 - Scot 4197 - Rem. 7½ - 1869 fps
Old West 155-gr - 24.5 - Scot 4197 - Rem. 7½ - 1920 fps

From: Metallic Silhouette Shooting, 2nd Ed., Elgin Gates
RCBS 168-gr - 20.0 - H322 or 25.4 - IMR3031

Notta lotta data.

[HORNET]

You could PM board member 7br and see what he's tried....

[Mugs]

Kent
Saeco #073 165 grn. 25.5 748 or 24.5 VV 135 both in the 1600-1700 fps. range. Very good for handgun silhouette.
Mugs
IHMSA 5940L

[Kent Fowler]

Thanks for the help, guys. I have a lot more to work with now.