Well after a lot of money, paying well over the odds for a LPA MIM I was all excited and eager to fit to my 2540.
What a shocking sloppy fit. I then compared all my breeches 3 crosman and a couple of aftermarket ones, what a difference in dovetails, no two are remotely the same.
In the end only one breech, an aftermarket stainless one from GMAC would accept the LPA without any slop or gaps.
I am not blaming LPA for this but am very surprised in the difference between breeches.
Rant over ;)
Gary
you know jb weld or some kind of epoxy could be used to fill in the gap.a release agagent in the dovetail or on the sight would insure it could it could be used without slop
Thanks Ed, I will try that when they ever become available again.
Just can't believe the variation from one breech to another, I assumed before it was just the LPAs that were poorly made.
Gary
Ed, you're spot on for solving a problem, but... breech dovetails should be standardized to usable tolerances AND the MIMs should be more durable for what they cost. We shouldn't have to jbweld or epoxy a new sight that is supposed to fit.
Mine fits "okay" but it did strip on one of the tiny front grubs during the initial installation... and I swear I didn't even get it to tighten at all. What a little PIG!
Of course, I hate how huge the sight picture is on it anyway, so it is just for looks on a permanently scoped gun. Useless past 7-8 meters IMO.
Ok. Rant over. ;)
i hear you on that!
so is it a sight issue or a crosman issue from what i hear crosman has some very tight tolerances when it comes to the qc dept and they dont let anything get by them especially barrels, with no rifling in them. or like the p-rod grip frame quickster didnt have to modify to fit his 1377 but 90+% of the other grip-frame owners had to modify either the sear or tube for it to work properly in their 1377's.
bottom line
which is out of spec the sight? or the breech?
Quote from: 1377x on October 12, 2012, 10:57:15 AM
i hear you on that!
so is it a sight issue or a crosman issue from what i hear crosman has some very tight tolerances when it comes to the qc dept and they dont let anything get by them especially barrels, with no rifling in them. or like the p-rod grip frame quickster didnt have to modify to fit his 1377 but 90+% of the other grip-frame owners had to modify either the sear or tube for it to work properly in their 1377's.
bottom line
which is out of spec the sight? or the breech?
I would say the breech, as all mine are different, even the crosmans are different.
Gary
is the stainless steel breech made by don cothran? or someone else?
Not sure, it was a GMAC part so not sure if Gordon made it or brought it in from DC.
Gary
ok! for some od reason im thinking he is selling dc parts im almost positive i read that a long time ago buti might be confusing that with the pacific pellet guns drop sear
Was the LPA mim sight you bought an OEM Crosman item?
The reason I ask is the LPA's Crosman sells are a contract item that use a very odball
74deg dove tail. Irregardless, if you intend to make it work I'd tell you to make the epoxy the last resort. Usually a fairly suitable fit can be had by "Peening" the dovetail and doing just a little bit of file fitting. That's the way it was always done by gunsmiths long before epoxy was invented.
Bummer on the fit issue ... :(
Quote from: fivestar45 on October 13, 2012, 10:54:30 PM
Was the LPA mim sight you bought an OEM Crosman item?
The reason I ask is the LPA's Crosman sells are a contract item that use a very odball
74deg dove tail. Irregardless, if you intend to make it work I'd tell you to make the epoxy the last resort. Usually a fairly suitable fit can be had by "Peening" the dovetail and doing just a little bit of file fitting. That's the way it was always done by gunsmiths long before epoxy was invented.
X2
how does one go about peening? a few different examples would help,like where to peen the dovetail.being born in the era of epoxy/jbweld and shoe polish/pam cooking spray.never really took the time to explore other options
i tried it on a project im working on and it didnt work the same way the gunsmith does it.
I think what has surprised me is that from what I read it was the LPA sight that was of questionable dimensions. But in my case it is the breeches that all vary.
Luckily I have a few different breeches to try.
Gary
I wanted the LPA sight for my modded 1322 but when i needed new irons they weren't available. I wound up getting the crosman Williams sight from amazon, cost about the same (arm + leg) and is not nearly as slick but the precision of the adjustment is better then the gun can use. Also you can't adjust it for very short distances. If you shoot at distance greater then 15 feet though this sight might work better for you...i know the temptation is to mod the sight but if i had this problem I'd just return it, i have tried modding stuff and now often then not i wind up spending more for an unsatisfactory result.
Example, i tried modding the stock 1322 trigger for weeks, polished and greased, fooled with springs and spacers etc and then started looking at triggers and realized i was better going straight to the p-rod trigger mod. The whole assembly was only $44 which is less then a custom trigger. Just an example and hope its not totally irrelevant
It seems to me that to much blame for poor fit has been laid upon the LPA mim sight itself. There are a few threads on the forum covering the subject and they all start out pretty much the same until someone starts thinking about the breech itself. Maybe I've just been lucky. I have 4 Crosman steel breeches, 3 long and 1 short. I have 3 mim sights that, with my tools all measure within. .002" in regards to the dovetail. Every one of them has a nice fit, no matter which breech I install the sight on.
Rant Complete ;)
Quote from: chongman on October 15, 2012, 01:29:18 AM
Rant Complete ;)
That was a rant?
C'mon, you didn't even sound worked up. ;)
Quote from: jdub on October 15, 2012, 04:09:57 AM
That was a rant?
C'mon, you didn't even sound worked up. ;)
I was being nice ;)
On Peening the breech dovetail. Lay the breech down on a flat full length wood block and hit the top rear edge of the dovetail down in maybe three, or four spots with a small hammer with a wedge face, or you can also use a small, dulled off, cold chisel. This will collapse a little of the dovetail and make the fit tighter. If you go a little too tight you just use a three sided needle file for a couple of strokes to bring it to where it fits best.
On mine anyway the LPA was massively too small on all but one of my breeches, which is quite a snug fit.
Not really an issue though now because I can't seem to get anymore MIMs anyway ;)
Gary