long throat on mcgowen 1-8 twist 223 bbl?--- LONG--

This is in no way a slam on Mcgowen, I just have some ? I bought a second hand (gunbroker) SS Mcgowen barrel. put the rifle together & took it shooting this weekend. all I had were mostly 55 gr hp's, sp's fmj's, & some green tip 62 gr fmj's. I was not impressed with the results. best 5 shot groups were right around 1-1/2 to 2" at 100 yards. I chalked it up to not having a heavy enough bullet for the twist. I bought some 75 gr amax bullets, & set about checking the max OAL I could use, with my sinclair seating depth gauge. the numbers I come up with up are wacky. I've gone over & over the formula & keep coming up with an OAL of about 2.855" to touch the lands! that puts THAT bullet out of the case! I dropped the bullet down the chamber, followed by a neck sized case. I could push the case into the chamber all the way home, with finger pressure. I guess my question is , is it normal for that twist of bbl to have such a long throat? or is it the bullet I'm using? or what the heck is going on? thanks in advance for any info or tips. If this is in the wrong forum, please move or remove. Mike.
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1:8 twist would be a normal twist for 80 gr or heavier bullets.

Try an 80 AMax.

Is this a new or used barrel???

not to dispute you, but its says for 1-8 twist right on the box of bullets. the barrel was "alleged" to have less than 100 rnds thru it, before it got to me. barrel is stamped 12/09

I have a custom Lilja 1-8 twist and they said to use up to 80gr bullets. I have had great luck with 77gr SMKs and 80gr Amax. The 75s should work well too, as far as I know. I am pretty new to this so I may be wrong.

well, I guess I'll load some of these 75 gr amax up & see what happens, before I jump to conclusions on the long throat. :-\

Someone either throated it longer or there has been about 5000 rds down the barrel right in a row. Mine was throated very short.

If you know of anyone who has a borescope have them give it a look.
sounds either long throat or if its shot out the firecracking will be obvious.
How does it clean up?

Are you using the Hornady 75gr A-max or BTHP? I know you said A-max, but the BTHP has a completely different ogive than the A-max. Also, is it supposed to be a standard .223Rem chamber or like a .223Wylde chamber(the Wylde having a good deal longer throat)? I can tell you max OAL in my RockRiver AR's chamber with 75gr A-max if you'd like.

Eight heads, 75 gr Amax. the barrel says 223REM[8]
Hi-tack, that's what I'm afraid of. Oh Well, I'm going to make up some loads with the 75's & 3 diff powders & see if I can get it to group. I think I'll keep the OAL at 2.390" & see if the different powders, & charge weights have any effect. If nothing looks promising, I'll have to make a decision on whether or not to pursue this farther, or start looking for another barrel. frankly, I was hoping this setup would shoot acceptable groups with the lighter bullets, that are interchangeable with some of my other 223 rifles. I'm not looking for miracles, but minute of angle would be nice. Mike.

My point was, somebody probably throated it long for 80 or 90 gr bullets.

Point taken, & I thank you for the advise.

I don't know guys......an 8 twist barrel begs to be throated long but for it to be so long that the 75g Amax isn't even in the case? Holy Crap!

dcloco, are you thinkin' what I'm thinkin? That barrel is just beggin' for a set back and re-chamber to 223 AI

;D


2gr8dgs, instead of dropping the bullet in the chamber end......take a case and cut a slit in the neck. Start the bullet of choice in the neck and rub a little gun oil on the ogive area. Chamber round (no powder/primer) and remove slowly. That might give you a better idea of what you're dealing with.

trappst, I just tried it. with the 75gr amax bullet just barely started in the case, say 2.650", it seats no further.

Quote:

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Originally Posted by trappst

dcloco, are you thinkin' what I'm thinkin? That barrel is just beggin' for a set back and re-chamber to 223 AI

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No....LOL! Need to run the 223 AI reamer in a touch deeper and make it a 222 Magnum AI (like my Super Duece). 80 gr AMax at 3150 fps is rather good. Flat shooting and still a whack at the end. Use 204 Ruger brass, neck up to 22 caliber....ta da! Use 223 AI dies for several neck sizes before you will have to FL size.

Dang it man! So, you cut a case and barely started a bullet....after chambering, the bullet didn't move. Correct?

Like this?

http://img.photobucket.com/albums/v2...algauge002.jpg

sorry, don't load 223 currently. this is 22-6mm w/60g Nosler

Just to back up what hi-teck said about throat lengths.....here are 2 rounds loaded to touch the lands in a 223 saami chamber. 040" freebore length.
http://i2.photobucket.com/albums/y48.../223throat.jpg

just to update, I tried to wring some accuracy out of the 75gr amax loads, to no avail. I ended up selling the barrel to a member. I found a brand new Stevens take off barrel for cheap. 22" 1/9 twist, sporter profile. Initial sight in showed promise with some v-max reloads I had lying around. today I tried fine tuning it ,& found something it likes. this 5 shot group at 100yrds (with flyer) is plenty good enough for me.
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