Jump to content
Rimfire World Community
Visit Brownells Visit AR15 Builder Visit Visit Site Visit Ballistic Advantage Visit Aero Precision Visit Cabelas
M4rk

adjusting velocity-bolt speed

Recommended Posts

where do u guys have ur set at? flush? all the way in? any pros and cons while having it on standard setting and using high velocity rounds?

Share this post


Link to post
Share on other sites

I had mine set in too far after I first got the rifle, and the spring wore badly & got kinked. New spring was $12, and Umarex told me: "Standard ammo - the bolt (adjustment screw) should be flush with the slide housing, and in four complete turns for High velocity ammo."

Someone has a picture posted that showed a destroyed buffer due to running high velocity ammo with it set to the standard position.

Share this post


Link to post
Share on other sites

I think maybe the bolt spring setting may be determined by the age of your rifle. I get the impression that the bolt springs have changed over time (re-designed?). The first Umarex video said to adjust screw all the way in for high-vel. ammo. Then we were told by the factory to set them 9 turns in for H. V. NOW it's four! Go figure.....

Share this post


Link to post
Share on other sites

So I wrote Umerax and got this reply today.

"If the gun is functioning fine I wouldn't adjust it. But if you do start

having feeding, extracting, or misfires issues then adjust the bolt speed by turning the allen head set screw 9 full revolutions to the right. If you have any other questions let me know."

Share this post


Link to post
Share on other sites

Thanks for the tips.  im gonna try 4 turns. Had misfires and extraction problems first time i took it to the range.  Will let you guys know if it works

Share this post


Link to post
Share on other sites

i think if its set on too tight, while u shoot standard velocity and sumtimes with hv ammo... the bolt comes back too fast and doesnt give the bullet to properly chamber... so it pinches it... thats wut ive noticed... so i did 4-5 full turns, since then, i had no issues.

Share this post


Link to post
Share on other sites

Hi guys I'm new to the forum . I just bought  A ISSC MK 22 and it wouldn't fire at all the store I bought it from took the gun back and let me trade it on a colt m4 carbine .after 250 rounds of cci mini mags and 250 rounds of cci blazer I have not had 1 probelm with the gun functions perfectly . I belive I have an updated version . The saftey is 90 degress and dust cover works also the buffer does not fall out and the bolt realse won't fall out either.  The first time I feild stirped it and cleaned it i noticed the bolt spring was turned in for high volocity . After my issc nightmare this gun is a caddy!! lovin it :)

Share this post


Link to post
Share on other sites

I had mine set in too far after I first got the rifle, and the spring wore badly & got kinked. New spring was $12, and Umarex told me: "Standard ammo - the bolt (adjustment screw) should be flush with the slide housing, and in four complete turns for High velocity ammo."

Someone has a picture posted that showed a destroyed buffer due to running high velocity ammo with it set to the standard position.

That would by link here. http://tactical22.net/forum/colt-umarex-general/broken-bumper-on-colt-22-m16/

Now I'm really baffled. My manual says to screw it in all the way. I thought I did that the first time, not wanting to damage anything I was a little cautious. After about another 1,500 or so rounds I see I have another broken bumper. I adjusted the spring in about another 3 full turns or so. It keeps going, didn't stop; however, I can really feel the difference in spring tension on the bolt. I may back it off a bit if it misfires.

BTW – I ordered two bumpers to avoid shipping costs for when it happens again. $20 out the door I think he said $7/each. I think Umarex should make the bumpers out of brass or aluminum.

Share this post


Link to post
Share on other sites

Hey Plinkster, Back when I got my Colt, the owners manual did not specify a setting for the bolt speed, and stated not to adjust it unless you had problems with a certain type of ammo. There was a Colt u-tube vid that specified 9 turns in, so I did that, and the spring was eventually destroyed. I run it at 4 turns in from flush, per email from Umarex Service Dept, as I only use high velocity ammo. Have not had any further issues. FWIW, the internals of this rifle are made from Zamak - which is a zink alloy. I think if the bumper was made of a harder material, it would be the Zamak  parts that would break.  You might want to think about ordering a new spring - it just might be weak, which would allow the bolt to impact the bumper. My 2 cents.

TM

PS - Your manual says to screw it in all the way??? How weird. I just checked the manual that is posted here, and it is like mine as far as the bolt setting is concerned, page #19. Can you scan that page in yours and post it?

Share this post


Link to post
Share on other sites

I ordered a new spring for mine a month or so ago, and it is DEFINITELY stronger (stiffer). I highly recommend you getting a new one. The original "cleaning" video on the Umarex/Colt website (used to) say turn the screw all the way in for Hi-velocity ammo, and all the way out for standard. I'm almost sure the springs were weaker back then. With the old spring, I used to set the spring at 4 turns when shooting Aguilla Sub-sonics with no problems. With the new spring, they will "stovepipe" at that setting. Have to back the spring all the way out to shoot them now.

Share this post


Link to post
Share on other sites

Thanks TM and wobblinwheel (WW)! Great input.

TM - My pdf manual from last year does not say that. I can't remember if it was from the cleaning video or my hard copy manual that's a couple years old, I'll have to dig it out. I do remember it was all in or out, I thought that was strange. I will readjust everything to about 4 turns in from flush.

I also understand your bumper material advice, good point.

WW - Good idea on the spring I'll order one. How much did that set you back?

Share this post


Link to post
Share on other sites

Join the conversation

You can post now and register later. If you have an account, sign in now to post with your account.

Guest
Reply to this topic...

×   Pasted as rich text.   Paste as plain text instead

  Only 75 emoji are allowed.

×   Your link has been automatically embedded.   Display as a link instead

×   Your previous content has been restored.   Clear editor

×   You cannot paste images directly. Upload or insert images from URL.


×
×
  • Create New...