Duplicate 7-08 in a smaller bore?

[LVJ76]

The particular range where the silhouette comps are shot at our club's range goes to 600 yards. I'm unclear on the actual distance to the rams. I would guess 500 meters, but I didn't want to assume anything. This is all new to us. We've attended one event and it looked like something she wanted to try. She has a blast with the small bore silhouettes and makes sure that we have them with us on every outing. I make a point of encouraging anything that she wants to try.

I thought so but wanted to be sure.

I shoot silhouette both smallbore and high power. For Smallbore the chikens are at 40m, javelinas at 60m, turkeys at 75m and rams at 100m. For high power the chickens are at 200m, javelinas at 300m, turkeys at 385m and rams at 500m (549 yds).

I use the 7mm-08 with the 150gr Sierra Matchking, with 44.5gr of IMR-4350 and get an average of 4,750 fps and no issues knocking down the rams. Have a Remington 700 Varmint with a 26" barrel. Set up with a Fahen Thumbhole stock and a Leopold Vari-x III 6.5x20 with the Target Dot recticle.

With smaller bore and lighter bullets the rams don't always get knocked down, same with some heavier bullets.

Back in the 70's the most common combination was the 308 with the 168gr Sierra MK's, however the Rams were an issue, they didn't always get knocked down. On the late 70's the 7mm-08 was developed as a wildcat, the 308 case necked down to 7mm.

With the same 168gr Sierra MK it did better at the Rams but some still didn't fall after they were hit especially on the lower part of the silhouette. So my dad and I tried put the 150gr Sierra MK and Bang, no more Ram issues.

My uncle tried the 7mm BR and a 6.5 Bryan I think it was called and had issues with the rams with both cartridges.

You need a balance of weight and speed for the Rams and I'm not sure a 140gr or lighter bullet will have enough to knock them down, but then again I have not tried them.

I have some 130gr Matchkings I want to try out, maybe push them fast at around 3,000 fps with IMR-4064 and see what happens.

I don't shoot as often as I used to and here the matches we have are pretty small with just a few shooters and we all use 308 or 7mm-08, so I really can't give more info on other cartridges.

However the 7mm-08 does work great, I highly recommend it. I also attached the NRA Rifle Silhouette rules in case you are interested.

Hope this helps

 

[ntsqd]

I could've done all of that, but since I wasn't initially looking to change the bullet mass it just seemed easier to use the same bullet mass & velocity for comparison's sake. That load development could take me in that direction later when we have more experience with the competition would not be a surprise.

They're shooting the monthly comp this weekend. If I can get away I was thinking to range what they actually shoot at for each stage.

 

[6.5BR]

Might post your question here - seems to be a good bit of knowledge on that board for your application. Once registered look at the 'High Power Rifle' forum section.

Good luck.

http://www.steelchickens.com/forums/

 

[Russler]

The 6.5 Creedmoor is a great option, the 140gr match load at 2700fps is very mild to shoot and carries over 1000 ft-lbs at 600

 

[LVJ76]

I thought so but wanted to be sure.

I shoot silhouette both smallbore and high power. For Smallbore the chikens are at 40m, javelinas at 60m, turkeys at 75m and rams at 100m. For high power the chickens are at 200m, javelinas at 300m, turkeys at 385m and rams at 500m (549 yds).

I use the 7mm-08 with the 150gr Sierra Matchking, with 44.5gr of IMR-4350 and get an average of 4,750 fps and no issues knocking down the rams. Have a Remington 700 Varmint with a 26" barrel. Set up with a Fahen Thumbhole stock and a Leopold Vari-x III 6.5x20 with the Target Dot recticle.

With smaller bore and lighter bullets the rams don't always get knocked down, same with some heavier bullets.

Back in the 70's the most common combination was the 308 with the 168gr Sierra MK's, however the Rams were an issue, they didn't always get knocked down. On the late 70's the 7mm-08 was developed as a wildcat, the 308 case necked down to 7mm.

With the same 168gr Sierra MK it did better at the Rams but some still didn't fall after they were hit especially on the lower part of the silhouette. So my dad and I tried put the 150gr Sierra MK and Bang, no more Ram issues.

My uncle tried the 7mm BR and a 6.5 Bryan I think it was called and had issues with the rams with both cartridges.

You need a balance of weight and speed for the Rams and I'm not sure a 140gr or lighter bullet will have enough to knock them down, but then again I have not tried them.

I have some 130gr Matchkings I want to try out, maybe push them fast at around 3,000 fps with IMR-4064 and see what happens.

I don't shoot as often as I used to and here the matches we have are pretty small with just a few shooters and we all use 308 or 7mm-08, so I really can't give more info on other cartridges.

However the 7mm-08 does work great, I highly recommend it. I also attached the NRA Rifle Silhouette rules in case you are interested.

Hope this helps

 

[6.5BR]

WOW!!!

I use the 7mm-08 with the 150gr Sierra Matchking, with 44.5gr of IMR-4350 and get an average of 4,750 fps and no issues knocking down the rams. Have a Remington 700 Varmint with a 26" barrel.

 

[LVJ76]

Might post your question here - seems to be a good bit of knowledge on that board for your application. Once registered look at the 'High Power Rifle' forum section.

Good luck.

http://www.steelchickens.com/forums/

Dang, I guess I'm stuck on the stone age here, looked in the forum and I guess lots of 6.5 cartridges are being used with the newer higher BC bullets. Good info thanks

 

[ntsqd]

WOW!!!
I use the 7mm-08 with the 150gr Sierra Matchking, with 44.5gr of IMR-4350 and get an average of 4,750 fps and no issues knocking down the rams. Have a Remington 700 Varmint with a 26" barrel.

Small typo, don't ya think?

At this point she hasn't given the go-ahead yet so I'm mostly exploring the options and getting the direction to take sorted out. It would come after the Valkyrie build. Which puts it third in line.

The Range Master did say that 140's in 7-08 were the bare minimum and that the shooter had to bring their A-game. I've no doubt that she can do that. Maybe not at first, but eventually. It will be more about building the strength to hold up the rifle for that long than anything else.
Recently a friend brought out his M95 to shoot when we visited his property and after determining that his 208 yd plate target was safe because the scope wasn't dialed in he offered to let others shoot it just for the experience of shooting a .50 BMG.
She drilled a hole in his target. Got up and feistily said "Don't tell me I won't hit the target!!!!!" That's my gal....

 

[rbTanzan]

PS: if you shoot the same weight bullet at the same velocity as the 7-08, you will have approximately the same recoil. To save on recoil it is best to go to a lighter weight bullet. Then even a slightly faster speed can still lower the recoil. The 6.5CM can shoot a lighter bullet than the 7-08 with similar or better BC. Even the 270 with a 129gn bullet will feel pretty similar to a 7-08 140gn at 2850. Here are their recoil energies, all assuming a very lightweight 7.2 pound rifle+scope set up:
6.5 CM 127gnLRX at 2825 (a max load), 600yd 1005 ft# impact, 13.5 foot pounds recoil
270 Win 129gnLRV at 3100 (near max), 600yd 1295 ft# impact, 18.7 foot pounds
7-08 140gn TTSX at 2850 (heavy, not max) 600yd 995 ft# impact, 16 foot pounds

So you can weigh the advantages of impacts at 600yards versus recoil in a light 7.2 rifle.

 

[6.5BR]

NTSQD - yes, that was recognized as a typo, over Swift speeds

Good luck to that young lady, she has the skills no doubt.

 

[LVJ76]

Small typo, don't ya think?

At this point she hasn't given the go-ahead yet so I'm mostly exploring the options and getting the direction to take sorted out. It would come after the Valkyrie build. Which puts it third in line.

The Range Master did say that 140's in 7-08 were the bare minimum and that the shooter had to bring their A-game. I've no doubt that she can do that. Maybe not at first, but eventually. It will be more about building the strength to hold up the rifle for that long than anything else.
Recently a friend brought out his M95 to shoot when we visited his property and after determining that his 208 yd plate target was safe because the scope wasn't dialed in he offered to let others shoot it just for the experience of shooting a .50 BMG.
She drilled a hole in his target. Got up and feistily said "Don't tell me I won't hit the target!!!!!" That's my gal....

Glad she liked it, my wife aldo shoots and she loves it. Shooting smallbore is the best practice she can do, you can replicate the rifle weight and with the low cost of ammo you can shoot all you want. With the high power you have to wait for the barrel to cool down and this slows down practice especially when time is restricted or in the summer when the barrels don't cool down quickly or at all.

For the hunter category also use a Remington 700, it's an SPS also in 7mm-08.

From what I just read the 6.5 CM and the 260 might be a good choice but again no experience with them.

 

[BountyHunter]

Most guys trying to knock steel off stands are looking at energy transmitted to the plate and 140 is minimum and 160 is better. AI or stay with straight 7-08, there is a reason that is the gold standard for that game

 

[Rflshootr]

When I looked at load tables the 6.5 CM was giving up 100 or more MV-FPS to the 7-08. But, that was load tables, not real world. Which is partly why my questions.

Have to take a look at the .260, since it was derived with the same approach as the 7-08 I'm more hopeful for it.

Think of it this way....the base of the bullet is like a piston. A larger bore diameter gives more surface area for the gases to push against. So all things being equal, the larger diameter will give more velocity with the same amount of powder/pressure. To increase velocity of the smaller bore size, you need more pressure, which means more powder, which means an increase in recoil. Just for curiosity sake, look at your load data and compare the 260, 7-08 and the 308 with equal weight bullets and you'll see the proof. They are all the same parent case and as long as the barrel lengths are approximately the same length, you'll see that the 308 will give more velocity but your b.c. will be lower for the same weight bullet. Now all you have to figure out is which combination suits your need the best.

 

[Stgraves260]

Just for discussion's sake let's say I/we wanted to duplicate 7-08 performance in the 140gr. - 150gr. bullet range, in a .25 or 6.5 mm bore. That is to say same bullet weight(s) at the same velocity(ies). I'm assuming that such a heavy in .25 could be found and included it so as to not reject it w/o due consideration. I'm thinking that the slightly smaller bore at the same bullet mass will force an even better BC, which I expect to translate into less wind drift. Our range is notorious for a L-R cross wind of varying strength.

The targets are steel and they have to be knocked off their stand. A 140gr. 7-08 is reportedly just about minimum to do this at the max distance of our local range (~600yds), IF the shooter does his/her part. Shooter is moderately recoil sensitive and weighs 110 lbs. max, so the 6.5/.378 Wby is not a contender for consideration.

A cursory glance at loads for the wunderkind 6.5 shows it's a little slow in comparison. What is real world? What other .25 or 6.5 calibers should I be looking at? Would prefer to stay in a short action if possible. Don't really need to surpass the 7-08 performance, merely equal it in a smaller bore and with the same bullet mass.

Do you reload? That will help me help you. LoL