I-almost-went-with-the-1&9-twist-but-decided-on-the-1&10.-I-think-the-1&10-will-be-able-to-stablize-the-longer-bullets-and-this-twist-rate-will-also-let-me-shoot-the-lighter-bullets.-I-talked-to-Barney-Lawton-and-he-said-the-1&10-twist-would-work-well.-Thanks-for-the-advice.
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Good-News!!!-(New-Rifle-Project)
- Thread starter wildcat
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Dan-B;-I-am-not-sure-right-now.-I-am-thinking-about-Kirby-for-the-gun-smithing.-I-ve-thought-about-going-with-the-7mm-Allen-Mag;-but-I-want-to-shoot-the-lighter-bullets-so-I-think-the-7mm-Allen-Mag-might-be-to-much.-I-will-probably-be-shooting-the-140grn-Ballistic-Tips-for-the-most-part.-They-have-really-good-BC(.485);and-I-will-be-able-to-pump-them-out-at-around-3500-fps;and-for-where-I-shoot-I-need-the-bullets-to-explode-on-impact.-I-think-the-7mm-Allen-mag-is-better-when-using-the-180-to-200grn-VLD-bullets.-I-have-talked-to-some-other-shooters-and-I-am-kinda-of-thinking-the-good-ol-7mm-Rem-Mag-might-be-the-way-to-go.-Norma-makes-the-brass;-I-wont-have-to-neck-it-down-or-neck-it-up-and-it-will-be-much-easier-to-find-good-load-data.-I-still-want-to-here-any-suggestions-you-guys-have-regarding-my-choice-of-7mm.
Thanks
Thanks
I've-decided-to-go-with-the-7MM-RUM.-I-am-trying-to-decide-if-I-need-to-change-my-twist-rate-on-my-barrel.-I-am-currently-going-with-a-1-10-twist;-however-I-am-thinking-the-1-9.5-might-work-better.-Others-have-told-me-the-1-10-will-stablize-all-7mm-bullets-but-from-what-I-can-see-everybody-who-is-using-a-7mm-are-using-either-the-1-9-or-1-9.5-twist-barrel.-I-am-thinking-the-1-9.5-is-the-best-way-to-go?-What-do-you-guys-think?
MagMan
Well-Known Member
Jake, I was able to get 3553 fps with the 160 AB's, 3250 with the 180 Bergers and all of 3100 with the 200 grain Wildcats. That was with Retumbo and a 30" 7 twist, soon to be a 8.75 thin land.
You should be able to stabilize almost everything 160 and above with a 1 in 9 twist.
My understanding is that it is better to over twist (fast) than to under twist (slow) to a certain extent. Even if you still wanted to shoot the 160's I have to believe the 1 in 9 will do just fine.
You should be able to stabilize almost everything 160 and above with a 1 in 9 twist.
My understanding is that it is better to over twist (fast) than to under twist (slow) to a certain extent. Even if you still wanted to shoot the 160's I have to believe the 1 in 9 will do just fine.
I-keep-changing-my-mind.-I-am-going-with-a-7mm-WSM-and-I-will-use-the-Norma-270-WSM-case-and-neck-it-up-to-7mm.-I-am-currently-going-with-a-1-10-twist-barrel-and-I've-been-told-that-the-1-10-twist-will-stablize-bullets-from-140-to-170grn-.-Berger-recommends-using-a-1-10-twist-with-their-168grn-VLD-bullet.-So-I-am-confused-on-which-barrel-twist-to-go-with.-I-am-going-to-be-shooting-140grn-Ballistic-Tips-pretty-much-all-the-time.-This-rifle-will-be-used-for-300-and-up-to-1000-yard-squirrel-shooting-and-the-140grn-Ballistic-tip-has-a-BC-of-.485-and-that-is-pretty-darn-good.-I-am-thinking-the-1-10-will-work-best-for-the-lighter-bullets;-and-I-will-still-be-able-to-use-the-162grn-bullets-too;-such-as-the-162grn-A-max.
Here is the update on the project. I decided to go with a 300-WSM Match Chamber with a .337 neck. The project is being designed around the 125grn Ballistic Tip with a muzzle velocity of over 4000+fps. Here are the updated specs;
1-300-WSM Match chamber for Norma Brass with a .337 tight neck.
2. Lawton 7500 1.450 Dia Stainless Steel Action, with fluted bolt and oversized bolt knob.
3. Krieger 30", 1-15 twist, 1.350 for 5" tapered to 1.250 at the muzzle, throated for the 125grn Nosler Ballistic Tip.
4. McMillan Tooley MBR Stock, 5-LBS Lead added to rear, removable front stud for bi-pod use, Color-80% Black, 10%White, and 10% Grey.
5. Jewel 2oz trigger.
6. Lawton 20-MOA Scope Base.
7. Vias Muzzle brake.
8. Nightforce 30mm Rings.
9. Nightforce 8x32x56mm NXS with Double Dot reticle.
10. Weight will be 23 to 25 pounds.
11. Lawton Stainless Steel trigger guard.
The rifle will be used for 1000 yard varminting. The bullet will be pushed at over 4000+fps. I've been reserching this project for some time and it is a very impressive chambering for varminting. Here is some awesome ballistic info. With the rifle sighted in at 200 yards, here are the elevation come ups:
1.-300 yards-1 MOA
2.-400 yards-2 1/2MOA
3.-500 yards-4 1/2MOA
4.-600 yards-6 MOA
5.-700 yards-9 1/4 MOA
6.-800 yards-12 MOA
7.-900 yards-15 1/2 MOA
8.-1000 yards-18 1/4 MOA
This is one Flat shooting rifle. Someone, on this site, gave me the windage adjustments and they were pretty decent with this bullet. The wind really does not get bad where we shoot, so it really wont be an issue. The 125grn BT has a BC of .366, and pushing it at over 4000+fps makes it an impressive combination.
I've seen some awesome video with this exact chambering being used and it was unbelievable what this bullet would do to a 20 pound groundhog. It lifted the varmint several feet in the air and blew it to pieces. You can see the video on Richards Custom Rifles web site as well as his varmint rifle chambered in the 300-WSM with a .337 neck. Richard has been avery helpful in helping me out with this project.
Here is the reload info and componets for this project;
1. Brass-Norma 300-WSM
2. Primers-Federal 210 Match primers
3. Powder-75grns Vhitavoria N550
4. Bullet-Nosler 125grn Ballistic Tip
Richard also indicated, he is getting PPC type groups along with 6 shoot groups at 100 yards measuring .162. See his site for pics and his favorite varmint rifle, the 300-WSM, it's an awesome story and rig. You can see some of the video on this site too.
Jake
1-300-WSM Match chamber for Norma Brass with a .337 tight neck.
2. Lawton 7500 1.450 Dia Stainless Steel Action, with fluted bolt and oversized bolt knob.
3. Krieger 30", 1-15 twist, 1.350 for 5" tapered to 1.250 at the muzzle, throated for the 125grn Nosler Ballistic Tip.
4. McMillan Tooley MBR Stock, 5-LBS Lead added to rear, removable front stud for bi-pod use, Color-80% Black, 10%White, and 10% Grey.
5. Jewel 2oz trigger.
6. Lawton 20-MOA Scope Base.
7. Vias Muzzle brake.
8. Nightforce 30mm Rings.
9. Nightforce 8x32x56mm NXS with Double Dot reticle.
10. Weight will be 23 to 25 pounds.
11. Lawton Stainless Steel trigger guard.
The rifle will be used for 1000 yard varminting. The bullet will be pushed at over 4000+fps. I've been reserching this project for some time and it is a very impressive chambering for varminting. Here is some awesome ballistic info. With the rifle sighted in at 200 yards, here are the elevation come ups:
1.-300 yards-1 MOA
2.-400 yards-2 1/2MOA
3.-500 yards-4 1/2MOA
4.-600 yards-6 MOA
5.-700 yards-9 1/4 MOA
6.-800 yards-12 MOA
7.-900 yards-15 1/2 MOA
8.-1000 yards-18 1/4 MOA
This is one Flat shooting rifle. Someone, on this site, gave me the windage adjustments and they were pretty decent with this bullet. The wind really does not get bad where we shoot, so it really wont be an issue. The 125grn BT has a BC of .366, and pushing it at over 4000+fps makes it an impressive combination.
I've seen some awesome video with this exact chambering being used and it was unbelievable what this bullet would do to a 20 pound groundhog. It lifted the varmint several feet in the air and blew it to pieces. You can see the video on Richards Custom Rifles web site as well as his varmint rifle chambered in the 300-WSM with a .337 neck. Richard has been avery helpful in helping me out with this project.
Here is the reload info and componets for this project;
1. Brass-Norma 300-WSM
2. Primers-Federal 210 Match primers
3. Powder-75grns Vhitavoria N550
4. Bullet-Nosler 125grn Ballistic Tip
Richard also indicated, he is getting PPC type groups along with 6 shoot groups at 100 yards measuring .162. See his site for pics and his favorite varmint rifle, the 300-WSM, it's an awesome story and rig. You can see some of the video on this site too.
Jake
