Author Topic: sight adjustment (Read 675 times)

hillbill · « **on:** April 13, 2004, 01:41:16 AM »

just got my first 45 acp 1911 type. was shooting it off the bench this weekend and it shoots good and is accurate but groups about 10" high consistantly with a standard 6 oclock sight picture. mil spec sights so no elevation adjustment is provided. im shooting 230 grn full jac wolf ammo in it. would a handload or diff weight bullet possibly help? or should i have the front site milled off and a new higher site installed? better sights wou;ldnt hurt much anyway. the gun is argentine colt made in the 50's. any ideas would be appreciated!

dclark · « **Reply #1 on:** April 17, 2004, 08:39:28 AM »

There are a number of solutions to adjusting the POI with fixed sights. Some are considerably more expensive than others. The sights on the Argie leaving a lot to be desired, as they are the mid-sized ones. Not as bad as the very early ones, but not nearly as visible as the later wide sights. Many like those fine for plinking; others hate them.

The front sight is staked on and can be removed by one who understands the process. You can buy another sight that will fit into the factory slot. There are a number of sight out there. Look in Brownell's catalogue. That may solve the problem.

However, if you are looking for a better solution, you may want to invest in a set of low mounted BoMar adjustable sights. They will be considerably more expensive and will require that the slide be milled to accomodate them properly; both front and rear. It is a very nice solution, especially for a variety of loads.

You can also have a number of low profile "combat" sights fitted to the slide, again requiring milling for a proper fit. Novak's come to mind as one of the more popular. They work well for loads that are developed for the point of impact.

The decision rests largely on the proposed use of the pistol, in my opinion and must be made by you. There is a ton of custom items for the 1911, and you just have to decide what you want.

dave clark

Thomas Krupinski · « **Reply #2 on:** April 17, 2004, 09:37:30 AM »

Quote from: hillbill

just got my first 45 acp 1911 type. was shooting it off the bench this weekend and it shoots good and is accurate but groups about 10" high consistantly with a standard 6 oclock sight picture. mil spec sights so no elevation adjustment is provided. im shooting 230 grn full jac wolf ammo in it. would a handload or diff weight bullet possibly help? or should i have the front site milled off and a new higher site installed? better sights wou;ldnt hurt much anyway. the gun is argentine colt made in the 50's. any ideas would be appreciated!

Before you mess with the sights, you may want to try some different loads with some lighter charges and same bullet weight.

When you said you were shooting off the bench, were you resting any portion of the pistol on a hard stand of any kind? If so you may have some bounce there any your point of impact may be different if held offhand or just resting your arms on the stand.

hillbill · « **Reply #3 on:** April 19, 2004, 12:59:24 AM »

thanks guys for all the good info!! ive tried everything but gun still prints too high. i think the new front sight is the next step. what is invloved in getting the old sight blade removed from the slide? ive found some taller ones but how do you decide exactly which height of one to use?

epochelyptikal · « **Reply #4 on:** October 18, 2004, 08:41:55 AM »

Check out this discussion:

http://www.graybeardoutdoors.com/phpbb2/viewtopic.php?t=32899

It includes info on removing the old site and basics of installing the new.

----Nevermind, I didn't realize it was you asking in that other forum topic as well!! Sorry! :oops:

Mikey · « **Reply #5 on:** October 19, 2004, 03:52:42 AM »

hillbill: before you go and have some expensive sight work done, that you may not need, see if you can find a gunsmith in your area who will, or can, examine the fit between the barrel and slide in that Argentine 45 and gunsmith a better fit.

I have seen a number of 45s that shot high, and all the gunsmith did was to make certain of the proper fit between the barrel and the slide and they would shoot properly. If you disassemble your pistol you will see that the inside of the slide and the barrel are supposed to match up with the barrel sitting squarely in the machined cuts inside the slide. Your barrel may not sit squarely and this is throwing your poi off. A good gunsmith can rememdy that for you and that piece should shoot fine. You might also need or just may need a longer barrel link - that's the swinging link on the bottom of barrel. You can get longer ones that should help lower your poi. But, talk to a good gunsmith about it before you go nutz on the sights.

I don't know if the Iowegan is following this thread but maybe he has some good recommendations. HTH. Mikey.

Iowegan · « **Reply #6 on:** October 19, 2004, 05:14:31 AM »

What Mikey is refereing to is using the barrel link to position the barrel so the sights register. This technique has been used by military armorers for many years. There are 5 different barrel link lengths. The longer the link, the lower the gun shoots. The shortest link measures .268", center-to-center between holes. The links increase in length by .005 up to .288". By trial and error, you can find a link that makes your gun shoot to POA.

A lot of Argentine Colt's had barrels swapped without regard to barrel lug length. This could easily make a gun shoot way high or low.

The Argentine Colt's use a narrow tenon front sight, should you decide to replace it.

epochelyptikal · « **Reply #7 on:** October 19, 2004, 05:38:37 AM »

Iowegian,

Is there any concern regarding feed/fire/eject failures with a longer or shorter barrel link?

My new SA GI 45 shoots a couple inches high and if that continues to be an issue with factory ammo (not set up to reload .45 yet, and not sure I'll shoot enough to warrant it yet), I think this would be the way to go vs. sight changes. I really like the GI 45s sights.

I'll pull the caliper out and measure center to center on my current link next time I have the pistol apart and maybe change step by step from there.

Thanks for the information!

Iowegan · « **Reply #8 on:** October 20, 2004, 10:18:17 AM »

epochelyptikal, The barrel lug depth runs about .060~.070". That means with the shortest link you will still have .040" of lug contact. The minimum lug contact is .020 for safe operation so using the shortest link still gives a healthy safety margin.

There are differences in how deep the slide lugs and barrel lugs are cut. I recently installed a Kart NM barrel in a Les Baer slide. They were both cut tight and I found the #5 link was too long and wouldn't allow the slide to go fully into battery. A #4 link worked perfect. More problems are encountered with the longer links because the lower mouth of the barrel may extend beyond the feed ramp thus causing feeding problems. The chamber mouth should be slightly forward of the feed ramp when the slide is locked to the rear.

Most new guns come with a #3 link (.278" C-T-C) so you have two adjustments above and below. Each .005 increment makes about a 2" difference in 25 yard zero. I would try the next size link (.283) to correct your POI. Be sure to measure your link first.

Brownell's sells Wilson barrel links in .005" increments, and Marvel in .003" increments. Each link sells for about $5.

epochelyptikal · « **Reply #9 on:** October 20, 2004, 12:01:38 PM »

Iowegan,

Thanks much. I'm eagerly awaiting my Wilson Combat 1911 Manual, so I can dig into the pistol completely and have a more rounded idea of how all these parts inter-relate. But the detailed information above is very helpful! I'll be making a run to an indoor range in the near future and will peg out exactly where the pattern falls at a documented 25 yards... Then I'll break out the Brownell's catalog.

Thanks again, man.