222 rem twist

[Biking]

Just picked up an extremely fine martini bench rest rifle with a custom barrel chambered for 222 Rem, been trying to develop a load for it and checked the twist.....here's the question, I've checked the twist rate several times and always the same answer. It appears to be 1 in 14 1/2 inches....is that common, possible, desirable, or ever specified on any rifles you've built?

 

[wapiti25]

The most common twist for the 222 rem is 1-14. You have a custom barrel so it may be a 1-14.5. I would use 50gr or lighter to start with. The 52 and 53gr target/match have been around for a long time. good luck

 

[areaone]

Try the Speer TNT in 50 gr, you will love that 222.

 

[40X Guy]

Biking, your twist rate is probably 1 in 14. Those .222's will shoot 50-53 grain class bullets into tiny groups. Try the Sierra 52 MK with IMR-4895 @ 23.5 grains with a Fed. 205M primer. The Sierras are very forgiving as far as tuning them and very accurate.

Frank

 

[Biking]

Thanks for all your replys...went out to the range today and tried 23.5 grains of CFE 223 hodgon's copper eating powder (been curious about it) behind Barnes 52 grain match burners at 100 yards and was very pleased...10 shots in the center ring that were covered by a 50 cent piece (remember those?)

 

[mac86951]

Keep working on loads, that 50cent piece will become a quarter, then a nickel, then a dime...

My 222rem loves flat based bullets, so be sure to experiment with flat base vs. BT at some point.
(also its a 1-14" twist).

-Mac

 

[Biking]

Mac, right you are on flat base vs. Boat tails pellets, my BSA regurgitates the boat tails all over the place and lasers the flat base bullets to aim point.

 

[BoydAllen]

Once a reasonable charge has been found, working with seating depth can give quite a bit of improvement. I would suggest a good 50gr. FB bullet, seated .006 longer than touching might be a good thing to try. five shots under a dime is not at all unusual. What sort of rest setup are you using? When going after the smallest groups, keeping track of the wind is pretty much mandatory.

 

[Biking]

Great suggestions and yes I'll purchase some 50 flat back grainers, because the Martini is a lever drop bolt action I need a good idea how to establish when the lands meet the bullet... tried the loose bullet in the case colored with a felt tip pen to show contact. I would call the effort inconclusive. Got any ideas?

 

[mac86951]

Great suggestions and yes I'll purchase some 50 flat back grainers, because the Martini is a lever drop bolt action I need a good idea how to establish when the lands meet the bullet... tried the loose bullet in the case colored with a felt tip pen to show contact. I would call the effort inconclusive. Got any ideas?

Best way I've heard of for relatively repeatable measurements is this:
Tools/parts needed, any pokey device that will allow you to "hold" a bullet on the lands
with controllable pressure (think soft).

Cleaning Rod with modified end, I use a Dewey standard rod, with a screw I've ground down
to be smaller than the bore, and flattened to measure to "point" of bullet.
I've also got a cylindrical ring with set-screw that fits around the cleaning rod diameter (lock-ring).

With Action closed and chamber empty, I insert the rod into the muzzle (carefully) and seat it
against the bolt face (make sure not the extractor or ejector). Then adjust the "lock-ring"
or other marking device to mark that position on the cleaning rod.

I then open the action and some how a bullet needs to be seated on the lands with light pressure
and insert the cleaning rod again. The distance between lock-ring and muzzle is your total OAL.
Repeat measurement 3-5 times and average. Get standard deviation low by using "equal" pressure
to seat the bullet in the lands (soft!)

Now, I need to mention that previously the Ogive was NOT measured, and bullets vary, so the accurate
measurement isn't complete yet. Next you need to take the SAME bullet you've used to measure and seat
it at the determined COL. Then using a bullet comparator that measures at the Ogive, you can make more
accurate loadings.

Repeat with 3-5 bullets if you really want to be accurate, or use the above method to get a relative measurement
and use testing to determine where you really want to be.


Easier way: Stoney Point or Hornady L-N-L comparator uses a threaded cartridge with bullet to touch the lands,
still do 3-5 measurements, and 3-5 bullets, but it makes measuring COL way faster.

-Mac

 

[Biking]

Mac....AWESOME, thanks for the great idea.

 

[mac86951]

Mac....AWESOME, thanks for the great idea.

No Problem, just remember that it is only as accurate as you make it, but in the end, use it as a starting point and
work seating depth, like load development. When you get an optimal seating depth, re-check your load too.

-Mac