Another 22-250 fast twist barrel question?

derbyacresbob

derbyacresbob

Well-known member
I am having a Hart 26" 1-8" twist barrel put on a Rem 700 action in 22-250 Remington.

I am going to have my gunsmith ream out .040 more free bore so I can shoot longer C.O.L. ammo.

What are your opinions on shooting the longer C.O.L. rounds with heavier longer bullets in the 22-250?

My Hornady Reloading book shows a C.O.L. of 2.490" for the 75 gr bullets for the 22-250.

 
I don't understand why you want more "freebore"?? The best part of a custom barrel for accuracy(IMO) is being able to cut a custom chamber for what you want to shoot.

I think it is best to have the chamber cut for the brass and bullet you want to shoot in the firearm if accuracy is your main concern.

"Freebore" may give a little more velocity. But at what expense. More pressure?? Less barrel life?? Heck just go to a 22-250 AI or a 220 Swift.

I just don't understand purposely cutting more "freebore" than needed?? Tom.
 
HOGGHEAD, I want to be able to reload my 22-250 ammo to the C.O.L. that Hornady recommends in their book, 2.490". When we put a dummy round in the chamber that was 2.500 C.O.L. it came out of the chamber 2.445".

I just did a search on "free bore" and then copied and pasted this below.

Why add more free bore:

The case for free boring is made this way, if you have a bullet seated deeply in a rifle case, the bullet is actually decreasing case capacity which in turn lowers the over all velocity of that imparticular bullet / case loading.

By adding more free bore, the bullet is then able to be seated out further thus increasing the case capacity which in turns allows you to add more powder to the case and thus an increase in velocity, usually quite a substantial increase in velocity.

How much can it help:

Usually increases are substantial to the point of standard calibers will be within reach of magnum velocities and magnum cartridges really get to actually earn the name magnum.
 
hogghed less presser hear is one @ 2.490 and 2nd @ 2.540 off my presser soft wear same load the one @ 2.490 has 58058 psi and same load @ 3.540 has 56632 psi difrenc of 1426 psi lower pressure goes to 2.540
or more boiler room. step the charge up to run the same psi is 35.1 of h380 3295 FPS @ 58078 psi gives you 15 fps and same presser.


Cartridge : .22-250 Rem. (CIP)
Bullet : .224, 75, Hornady BTHP M 2279
Useable Case Capaci: 39.842 grain H2O = 2.587 cm³
Cartridge O.A.L. L6: 2.490 inch = 63.25 mm
Barrel Length : 26.0 inch = 660.4 mm
Powder : Hodgdon H380

Predicted data by increasing and decreasing the given charge,
incremented in steps of 2.0% of nominal charge.
CAUTION: Figures exceed maximum and minimum recommended loads !

Step Fill. Charge Vel. Energy Pmax Pmuz Prop.Burnt B_Time
% % Grains fps ft.lbs psi psi % ms

-20.0 74 27.76 2664 1182 31192 7800 92.6 1.520
-18.0 76 28.45 2727 1239 33215 8022 93.7 1.481
-16.0 78 29.15 2790 1296 35363 8236 94.7 1.443
-14.0 80 29.84 2852 1355 37642 8441 95.6 1.405
-12.0 81 30.54 2914 1415 40061 8636 96.4 1.364
-10.0 83 31.23 2976 1475 42629 8820 97.1 1.325
-08.0 85 31.92 3038 1537 45354 8993 97.8 1.287
-06.0 87 32.62 3099 1600 48247 9153 98.4 1.250
-04.0 89 33.31 3160 1663 51321 9301 98.9 1.215 ! Near Maximum !
-02.0 91 34.01 3220 1727 54586 9435 99.3 1.182 ! Near Maximum !
+00.0 92 34.70 3280 1792 58058 9555 99.6 1.149 !DANGEROUS LOAD-DO NOT USE!
+02.0 94 35.39 3340 1858 61752 9660 99.8 1.118 !DANGEROUS LOAD-DO NOT USE!
+04.0 96 36.09 3399 1924 65683 9750 100.0 1.088 !DANGEROUS LOAD-DO NOT USE!
+06.0 98 36.78 3457 1991 69872 9824 100.0 1.059 !DANGEROUS LOAD-DO NOT USE!
+08.0 100 37.48 3515 2058 74338 9888 100.0 1.031 !DANGEROUS LOAD-DO NOT USE!
+10.0 102 38.17 3573 2126 79105 9950 100.0 1.004 !DANGEROUS LOAD-DO NOT USE!

Results caused by ± 10% powder lot-to-lot burning rate variation using nominal charge
Data for burning rate increased by 10% relative to nominal value:
+Ba 92 34.70 3407 1933 68503 9232 100.0 1.070 !DANGEROUS LOAD-DO NOT USE!
Data for burning rate decreased by 10% relative to nominal value:
-Ba 92 34.70 3100 1601 47773 9489 95.6 1.255










Cartridge : .22-250 Rem. (CIP)
Bullet : .224, 75, Hornady BTHP M 2279
Useable Case Capaci: 40.340 grain H2O = 2.619 cm³
Cartridge O.A.L. L6: 2.540 inch = 64.52 mm
Barrel Length : 26.0 inch = 660.4 mm
Powder : Hodgdon H380

Predicted data by increasing and decreasing the given charge,
incremented in steps of 2.0% of nominal charge.
CAUTION: Figures exceed maximum and minimum recommended loads !

Step Fill. Charge Vel. Energy Pmax Pmuz Prop.Burnt B_Time
% % Grains fps ft.lbs psi psi % ms

-20.0 73 27.76 2649 1169 30625 7809 92.4 1.531
-18.0 75 28.45 2712 1225 32592 8034 93.5 1.493
-16.0 77 29.15 2774 1281 34679 8251 94.5 1.455
-14.0 79 29.84 2836 1339 36892 8459 95.4 1.419
-12.0 80 30.54 2898 1398 39238 8657 96.2 1.378
-10.0 82 31.23 2959 1458 41726 8844 97.0 1.338
-08.0 84 31.92 3020 1519 44365 9021 97.7 1.300
-06.0 86 32.62 3081 1581 47163 9185 98.3 1.263
-04.0 88 33.31 3142 1644 50133 9337 98.8 1.228 ! Near Maximum !
-02.0 90 34.01 3202 1707 53285 9476 99.2 1.195 ! Near Maximum !
+00.0 91 34.70 3261 1771 56632 9601 99.5 1.162 ! Near Maximum !
+02.0 93 35.39 3320 1836 60188 9711 99.8 1.131 !DANGEROUS LOAD-DO NOT USE!
+04.0 95 36.09 3379 1901 63969 9807 99.9 1.100 !DANGEROUS LOAD-DO NOT USE!
+06.0 97 36.78 3437 1967 67991 9887 100.0 1.071 !DANGEROUS LOAD-DO NOT USE!
+08.0 99 37.48 3495 2034 72274 9954 100.0 1.043 !DANGEROUS LOAD-DO NOT USE!
+10.0 100 38.17 3551 2101 76838 10018 100.0 1.016 !DANGEROUS LOAD-DO NOT USE!

Results caused by ± 10% powder lot-to-lot burning rate variation using nominal charge
Data for burning rate increased by 10% relative to nominal value:
+Ba 91 34.70 3389 1913 66787 9288 100.0 1.081 !DANGEROUS LOAD-DO NOT USE!
Data for burning rate decreased by 10% relative to nominal value:
-Ba 91 34.70 3081 1580 46632 9513 95.3 1.269
 
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Originally Posted By: derbyacresbobHOGGHEAD, I want to be able to reload my 22-250 ammo to the C.O.L. that Hornady recommends in their book, 2.490". When we put a dummy round in the chamber that was 2.500 C.O.L. it came out of the chamber 2.445".


When I read your OP I thought we were on the same page. But wasn't 100% positive.

I think you are just representing what you want to do with different terminology.

Freebore is to be left after you have seated the bullet. Not to add additional room for larger bullets. Freebore is a concept that was perfectd by Roy Weatherby. Read what Roy says about freebore.

What I am trying to say is do not limit yourself to a certain amouint of frebore. Do what 2-much said to do and have the chamber cut exactly to the case and bullet you want to use. This is the real reason for cutting a custom chamber-and not to just add additional space.

For my way of thinking(including Roy's) freebore is more room for pressure to be generated before the bullet actually touches the lands. Therefore more velocity can be attained. However I have found that accuracy can suffer a bit if the rifle has freebore after the bullet is seated. Pick your bullet and have the chamber cut to the exact length you want. I think you will see a more accurate rifle than just adding an arbitrary amount of freebore-or longer chamber. Just an opinion. Tom.
 
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With heavy bullets in the 22-250 you might want to add another inch or two of barrel.You will need to burn a little slower powder with those pills or you'll blow primers like crazy.And you can use some of the extra to have the barrel set back when you burn out the throat.
In my fast twist I finally just did a 28 inch barrel.Then had it chambered in Ackley Improved.It is still shootin great after about 1100 rounds.
 
Originally Posted By: derbyacresbobSo would throated longer be the term I want to use instead of free bore?

Thanks

Yes it would be. Talk to your smith. Work up a dummy load with the brass and bullet that you want to shoot. Then send him the dummy round and have the chamber cut to the dimensions that you are specifying.

Do some research into the bullet you want to use. Find out whether it shoots better into the lands or.015 to .020 off the lands. Discuss this with other shooters and your smith.

Then as said above. Get your dummy round put together using your dies and have the smith cut you a chamber to fit your needs. IMO that is the best way to go.

At least it is the way that the few custom chambers that I have were built. And were recommended to me by the fellows doing the work.

Maybe 2-much will chime back in with an opinion on this. His opinios are pretty well thought out(don't tell him I said that) on this. Tom.
 
how many reloads on the brass? I show you @ 65678 psi with moly'd this was 22". moly'd drops press by 1980 psi .thats only 6938 PSI over (CIP)spec. now cram it into lands & add 7200 psi on top of that 14138 over (cip) just a gess but I will bet I am with in less than 1000 psi of being right.


no offence Dont give us your load some one might just try IT!!!!
 
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I would have a custom reamer made if you are going to long freebore.
A 22-250 doesn't technically have freebore and the throat starts at larger
than bullet diameter. You are going to leave the bullet loose in the bore,
a true .224 caliber freebore like a Wylde chamber has would suit your
purposes better. I may be able to be accomplished with a throating reamer
without going custom but I am not that familiar with the actual reaming
processes.
 
Quote:What are your opinions on shooting the longer C.O.L. rounds with heavier longer bullets in the 22-250?

A heck of a lot of fun while it lasts, but that won't be for all that long.

22-250s aren't known for long barrel life even with a 1:14 twist. The 1:8 twist I had succumbed after considerably less than 1000 rds. It was fun while it lasted though.

As has been pointed out, freebore is the "jump" the bullet has to the lands. It allows for more velocity without a corresponding increase in pressure, but (forgive me Roy) has not proven to be the best method to improve accuracy.
 
Originally Posted By: tnshootistI guess this is a dumb question but,why not shoot a .243?Just asking.

Basically because there is a substantial difference between the 75 grain BC in 22 caliber vs the BC of the 75 grain 243 bullet. And most people consider the 22 caliber as the largest varmint round that you can still see impacts with if you have a rfle adapted to do so with. You really need to go to the 100 grain bullet in the 243 before you can get the same BC as a 75 in 22 caliber. And a 100 grain bullet is really considered(IMO) too big for varmints and vermin. Plus a bunch more recoil.

Certainly there is nothing wrong with the 243 caliber. Lots of people like them very well. I just like the 22-250. Just different strokes for different folks. Tom.
 
I have had several 22-250's and like them a lot.I have a 243 now and like it also.
I had a 22-250 when I was still on the farm as a young man and boy did it shoot good.I really could hit anything I could see.But now 40 years later I can't find one that shoots as good as it did.I don't know what the problem could be.
 
Originally Posted By: 204farrhow many reloads on the brass? I show you @ 65678 psi with moly'd this was 22". moly'd drops press by 1980 psi .thats only 6938 PSI over (CIP)spec. now cram it into lands & add 7200 psi on top of that 14138 over (cip) just a gess but I will bet I am with in less than 1000 psi of being right.


no offence Dont give us your load some one might just try IT!!!!

Oldest lot of brass for that rifle had 12+ firings on it and the pockets were still tight. Funny how you're scared for me after running the loads on your "computer program" and with 1200+ "real" rounds through the rifle in temps from 0-90* there were never any pressure issues/signs. I know you understand that different burn rates of powder's will give you different speeds before you get into pressure, so what powder were you running to come up with your theoretical pressure numbers?

Tell us about your 22" 22-250 w/75's and what speeds you are getting?
 
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Originally Posted By: HOGGHEADOriginally Posted By: tnshootistI guess this is a dumb question but,why not shoot a .243?Just asking.

Basically because there is a substantial difference between the 75 grain BC in 22 caliber vs the BC of the 75 grain 243 bullet. And most people consider the 22 caliber as the largest varmint round that you can still see impacts with if you have a rfle adapted to do so with. You really need to go to the 100 grain bullet in the 243 before you can get the same BC as a 75 in 22 caliber. And a 100 grain bullet is really considered(IMO) too big for varmints and vermin. Plus a bunch more recoil.

Certainly there is nothing wrong with the 243 caliber. Lots of people like them very well. I just like the 22-250. Just different strokes for different folks. Tom.



I agree with you Tom, Though I can spot my own hits with my heavy'ish 243AI and 105's, it was easier to do so with the '250.
 


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