ar10 I think I have a bit more free bore than yours
Mk248 mod 1
- Thread starter bigal1964
- Start date
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barrel is 1.250 at the chamber and .850 at muzzle
from what I have read on this forum my gunsmith is the guy that fixed the overpressure problem for the government in this rifle.
ShtrRdy
Well-Known Member
Here's what I found for the 215 Hybrid
ar10ar15man
Well-Known Member
no because if you did you would not have a mk248mod1 chamber.
i used the same reamer the mil uses, the same bbl they use
mine is 2.940, the 220 smk is 3.502, the 230 berger is 3.706
i used the same reamer the mil uses, the same bbl they use
mine is 2.940, the 220 smk is 3.502, the 230 berger is 3.706
ar10ar15man
Well-Known Member
lol
that is funny
there is no problem
it was DESIGNED FOR 68100
STD CHAMBERED RIFLES PROBABLY HAVE AN OVER PRESSURE ISSUE WITH THIS ROUND. MK13'S CHAMBERED WITH THE NAVY MK13 REAMER DO NOT.
please direct me to these threads where your gunsmith fix an "over pressure" issue for the mil with the mk248mod1 in a mk13 rifle.
please note the velocity, powder, case, bullet, primer, oal length are all listed in the mil spec.
that is funny
there is no problem
it was DESIGNED FOR 68100
STD CHAMBERED RIFLES PROBABLY HAVE AN OVER PRESSURE ISSUE WITH THIS ROUND. MK13'S CHAMBERED WITH THE NAVY MK13 REAMER DO NOT.
please direct me to these threads where your gunsmith fix an "over pressure" issue for the mil with the mk248mod1 in a mk13 rifle.
please note the velocity, powder, case, bullet, primer, oal length are all listed in the mil spec.
ar10ar15man
Well-Known Member
from the spec on 300 win mag match ammo (mk248mod1) from mar 17, 2009
3.6.1 Velocity. (M105) [The corrected average muzzle velocity of the cartridges conditioned at 70°± 5° Fahrenheit (F) shall be 2,850 ± 50 ft/sec. feet per second (fps)]. The standard deviation of the corrected muzzle velocity at 70°± 5° F shall not exceed 15 fps. This test shall be conducted in accordance with paragraph 4.5.6.
3.6.2 Chamber Pressure. (M106) [The corrected average chamber pressure shall not exceed 68,100 pounds per square inch (psi) at 70°F.] Neither the chamber pressure of an individual sample test cartridge nor the average chamber pressure plus three standard deviations of chamber pressure shall exceed 78,900 psi. This test shall be conducted in accordance with paragraph 4.5.7.
3.6.1 Velocity. (M105) [The corrected average muzzle velocity of the cartridges conditioned at 70°± 5° Fahrenheit (F) shall be 2,850 ± 50 ft/sec. feet per second (fps)]. The standard deviation of the corrected muzzle velocity at 70°± 5° F shall not exceed 15 fps. This test shall be conducted in accordance with paragraph 4.5.6.
3.6.2 Chamber Pressure. (M106) [The corrected average chamber pressure shall not exceed 68,100 pounds per square inch (psi) at 70°F.] Neither the chamber pressure of an individual sample test cartridge nor the average chamber pressure plus three standard deviations of chamber pressure shall exceed 78,900 psi. This test shall be conducted in accordance with paragraph 4.5.7.
im sorry it on a different forum called snipers hide. his user name is LongRifles Inc. posted on june 29 2017
if you go to snipers hide and search LongRifles Inc. and go to the june 28 2017 post you will see a rifle that he built just like mine. he builds them on a rem 700 LA.
Thank you shtr!
ar10ar15man
Well-Known Member
sorry need more info for a search by date they start now and go back. a 2017 thread is a little late to be "fixing" a 2009 design.
actual thread title
actual thread title
ar10ar15man
Well-Known Member
so not he did not FIX a problem the mil had with the ammo and the rifle AND PRESSURE
he was working on a private party rifle WITHOUT a spec bbl. so who knows what reamer was used..( SPEC BBLS ARE mk13 from LILJA)
one single private party rifle
in 2012 THREE YEARS AFTER IT WAS IN USE BY CRANE/SEALS
FROM HIS SITE
Your search for "MK248MOD1" did not yield any results.
he was working on a private party rifle WITHOUT a spec bbl. so who knows what reamer was used..( SPEC BBLS ARE mk13 from LILJA)
one single private party rifle
in 2012 THREE YEARS AFTER IT WAS IN USE BY CRANE/SEALS
FROM HIS SITE
Your search for "MK248MOD1" did not yield any results.
Last edited:
Jeffrey Van Zandt
Well-Known Member
most remington actions top out around 74-76 of H-1000 I use 77.5 and it works good but brass and temp and jump jam all can over press you I set OAL and my mags OAL just work up a load you like what twist is your barrel?
