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January 7th, 2014, 02:01 PM
#1
Reloading - Bullet selection vs Barrel Twist
I recently bought a Browning X-Bolt Varmint Stalker 22-250 Rem. Prior to this I had already started assembling what I would need to reload for this rifle. (I plan ahead - mostly, which is the reason for this post).
As part of my preparation I bought 500 Hornady 22 Cal .224 53 Gr V-Max boat tails. Now you can imagine my displeasure as I sit down to begin reloading only to read the caveat in the Hornady 9th Edition manual. These bullets will not stabilize in barrels slower than 1:14. Of course my new Browning is in fact a 1:14 twist.
At this point I am feeling rather ticked at myself and figure the only solution is to learn something from this. So I set about going to read more about how bullet stabilization is measured and applied. In a nutshell it is simply a function of speed and twist to yield sufficient revolution of the bullet as it leaves the barrel. A bullets stability is a function of its caliber and overall length (I am summarizing so please don't think that these are the only factors).
More reading can be done here:
http://en.wikipedia.org/wiki/Rifling...llet_stability
So, now that I have a better idea of what the factors are, I found two links to help with this.
http://www.jbmballistics.com/cgi-bin/jbmstab-5.1.cgi
and
http://www.bergerbullets.com/litz/TwistRuleAlt.php
If you are reloading and having issues with accuracy and consistency it may be worth some effort to run the numbers and see if the issue isn't related to twist ratio.
In my case I managed to resolve the problem for the most part by adding speed. With a 39.1 Gr load of CFE 223, these bullets leave the barrel at +3950 fps (I have a chronograph).
They are not as accurate as cheap Remington bulk 55 Gr SP but not as bad as I would have thought.
There is room for all God's creatures - right next to the mashed potatoes!
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January 7th, 2014 02:01 PM
# ADS
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January 7th, 2014, 02:04 PM
#2
Sell them to me my new savage has a 1 in 12 twist rate. I always do my research prior to buying guns.
Last edited by pbonura; January 7th, 2014 at 02:07 PM.
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January 7th, 2014, 04:52 PM
#3
Has too much time on their hands
You did say "slower than 1:14", but you do have a 1:14 barrel so you probably are okay, as long as you are obtaining good velocity. The twist rate problem is VERY common in the .250 Savage, early rifles were 1:14, later rifles 1:10. Legend has it that 100-grain bullets are too heavy for the 1:14 twist, but I have always gotten good results even with 100-grainers by keeping velocity up as high as I could safely get it.
Don't write those bullets off yet; they may be excellent performers in your rifle.
Edit....I re-read your post and I see you're already "up to speed", as it were. The cheap Remmy's are likely a hair more accurate because they are shorter, not being boattails. Same is true with my .250's; I can't hit a barn door with a Nosler Partition 100 but Rem flatbase CoreLokts go easily sub-MOA. They are shorter by about .1 inch....
Last edited by Kilo Charlie; January 7th, 2014 at 04:56 PM.
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January 7th, 2014, 06:58 PM
#4
When I run into similar issues I go to a flat based bullet. I don't experience much advantage to boat tails until beyond 350yd to 400yd .
You're on the right track, many barrels will shoot what they aren't supposed too. You just have to do as you did and try them.
Keep in mind temps and air density, I can shoot A max in a 1/9 .223 sometimes, depending on temperature and air density.
Last edited by skypilot; January 7th, 2014 at 07:02 PM.
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January 8th, 2014, 02:44 PM
#5
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January 14th, 2014, 12:16 PM
#6
A lot more factors than twist. I had a 50/90 with a 38 twist that put 600 grainers in one hole all day
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January 14th, 2014, 12:49 PM
#7
Also, just another thing to consider...not all barrels are "exactly" the twist they claim they are. Some 1/9.25 may be closer to 1/10 or a 1/10 may be closer to 1/10.5. I check all of my rifle barrels to see what the actual twist is. Then I try hand loads from the bullets too "light/short" for the twist and too "heavy/long" for the twist to determine the correct bullet for that barrel.
GrouseWhisperer's example is basically the same, try it and see what will work.
I also don't load develop for a barrel until a minimum of 150-250 rds down the barrel.
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January 14th, 2014, 06:04 PM
#8
I dont reload but my Tikka with 14 twist shoots 50 and 55g Hornady factory ammunition very well. 1" or less at 100 yards.
"If guns cause crime, all of mine are defective."
-Ted Nugent
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January 15th, 2014, 06:54 AM
#9
Thanks for the feedback. I have made up a number of loads for different bullet weights including the 53 Gr V-Max boat tails. If I can get them going fast enough (not to the point of risk or danger to me or the rifle) I may be able to use them. I hope to get out this weekend to put a few (10 or more) into paper. Shouldn't take long to see how this story will play out. I also bought a factory box of Hornady V-Max to shoot along side for comparison.
There is room for all God's creatures - right next to the mashed potatoes!
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January 15th, 2014, 11:13 AM
#10
Keep in mind what is most accurate @ 100 yds. won't necessarily be what is accurate @ say 400 yds.
I load test at 300 yds and then shoot from 100 yds to 500 yds., or the furthest distance I plan to depend on that loading, then I true my dope.
I would guess you'd want the 22-250 to have legs out to 400+ yds also.