7mm IHMSA cast bullet loads???

[huntingfool1]

I am new to the site but a silhouette shooter from the late 70's and 80's. I have been out of the sport since then but have the desire to start making some matches once again. ( All categories ) I am a cast bullet shooter and recently acquired an XP-100 chambered for the 7mm IHMSA and was wondering if anyone out there has any cast bullet data for the round?

[high standard 40]

I don't load cast bullets for a 7IHMSA (I don't have one) but I do load for a Contender 7 TCU, an XP100 7 TCU, and an XP100 7BR. In all of these I use the exact same load as I used for jacketed bullets. With cast, it's not really about choosing "X" bullet and "Y" powder. It's much more important to correctly fit the bullet to your chamber and bore and use an appropriate alloy. Size the bullet to fit your chamber throat and seat the bullet so that the nose engraves the rifling and then work with powder selection and charge level lastly. You can't really just buy a mold because it has worked for someone else. Molds vary from lot to lot as do chambers. You have to adjust your bullets to fit your gun. I have purchased molds that produced a bullet that would not work in any of my guns because the bullets were undersized for my particular application. Yet others have used the same mold and it worked for them. Different lot of molds and different chambers equals different results. Bullet fit is the key to success.

[260 Striker]

HF1 - I used 19.0 grains of SR4759 with a RCBS 165 silhouette bullet this year in a XP 7IHMSA-X and it was very, very accurate. The bullets were cast out of wheel weights, sized to .310 with Hornady gas checks. I also used a Redding .300 bushing die as a nose die to just round out the noses. Can't remember what my seating depth was but I go against all the advice about loading to engrave the rifling and still get enough accuracy for 200 meter shoot off targets. I agree that moulds, guns, lube and any other variable in CB shooting is just a matter of finding what your gun likes. The SR4759 load is very mild too so doesn't beat you up during a match. The 7IHMSA-X (aka 7INT-X) is a great cartridge and easy to find an accurate load, especially with cast bullets. The RCBS 145 silhouette mould is also very accurate in many 7mm guns I just happened to have more of the 165s to play with. If you have the 145 mould try the same 19.0 grains with it.

[huntingfool1]

HF1 - I used 19.0 grains of SR4759 with a RCBS 165 silhouette bullet this year in a XP 7IHMSA-X and it was very, very accurate. The bullets were cast out of wheel weights, sized to .310 with Hornady gas checks. I also used a Redding .300 bushing die as a nose die to just round out the noses. Can't remember what my seating depth was but I go against all the advice about loading to engrave the rifling and still get enough accuracy for 200 meter shoot off targets. I agree that moulds, guns, lube and any other variable in CB shooting is just a matter of finding what your gun likes. The SR4759 load is very mild too so doesn't beat you up during a match. The 7IHMSA-X (aka 7INT-X) is a great cartridge and easy to find an accurate load, especially with cast bullets. The RCBS 145 silhouette mould is also very accurate in many 7mm guns I just happened to have more of the 165s to play with. If you have the 145 mould try the same 19.0 grains with it.

I appreciate the information but am a bit puzzled about sizing the 7mm bullets to .310. Also, have you experimented with any other powders?

[LOCKHART]

I used a Lyman mold for my 7br, cant remember the number, but bullets came
out of it at 179 grains, cast in cold-water quenched wheel weights and in front
of 22.5 grains of H-322. Good accurate load! And, in my 7int, I use 18 grains
of SR-4759, very accurate!

[260 Striker]

HF1 - Guess I should proof read my replies better. I was talking about my 30 caliber cast bullets. Sorry!!! For my 7mm bullets I use the RCBS 145 and 165 mould blocks and size them to .285 then use a .277 H&I die to nose size the bullets down to the driving band. Just rounds out the noses at the parting lines and makes them true bore riders. SR4759 is a great powder and the 18.0 grain load will probably do anything you need. That powder will soon disappear since the last batch was made in March/April so you might want to experiment with AA7544. About 22 or 23 grains of 5744 would do the same as the 18.0 of 4759 and will be very accurate and pleasant to shoot. 7IHMSA and 7IHMSA-X are both great cast bullet cartridges.

[LOCKHART]

I have been stocking up on SR-4759 since I heard the news. I have managed
to put together about 12 lbs, now, so that should last me for a long time.

[huntingfool1]

Thanks for the info. Now if I could just find some 4759 or 5744, I could start working on a load. Since this round is built off the 300 savage case, could one also look at some of the powders listed for use under the 300 savage cast bullet loads?

[high standard 40]

If you plan to shoot this gun for many years, and you want to use 4759 or 5744, you are faced with buying heavily into those powders now as they are both scheduled to be discontinued (or so I heard). H4895 was always a very popular powder for the 7 IHMSA and it responds well to reduced loads. As I mentioned in my previous post, you can use the same loads for cast as you do for jacketed bullets if the bullets fit your chamber and are of the proper alloy. I do it all the time with outstanding results. As far as loads for a 300 Savage, they would not be a direct replacement for the 7 IHMSA because you have to consider bore volume. The 7 IHMSA also has less body taper and a sharper shoulder angle. Two different animals.

[LOCKHART]

I have found that 7-08 load data will work pretty well for 7mm INt, just
start low, and work up to full loads just as you would with any other
cartridge.