Help ... Think My Scope Took a Dump ?

[67rschev]

Hey All ,

I got a chance yesterday afternoon to brake away for a few hours and get a little therapy at the range . I had around 30 left over accuracy round I needed to shoot to free up the brass , and another 30 I threw together with some Hornady 168 blems that I use for practice fodder

The gun was cleaned after the last 150+ range session , and all went well with my pet loads shooing a couple groups in the .3s . Went on to shoot the blems , Hornady 168 HPBT , Lapua brass, a mild load of Varget 43.6 grains . The first three groups were what I had experienced the one time I have shot this combo before printing .5 - .7 or so . On the 4th group , the first shot was a flier at 2 O'Clock a good 2 inches off the target . The following four then grouped fair . Next group they started to open up and the 4th shoot went 2 inches out at 8 O'Clock . Group six was peppered in a three inch group .

Promptly checked all the usual suspects , action screws good , rings good , rings to rail good , rail good .

I am beginning to suspect the scope crapped out on me . Giving the gun a good cleaning tonight , and will load up some of my known good loadings for this piece and head back to the range latter this week with another scope in hand . The only scope I had buy the farm on me , lost parallax so I'm not sure if anyone has seen one go out like this . Any other ideas what went wrong ?

Here is a picture of said last 6 groups

[C Ward]

What kind of scope ?

[67rschev]

SWFA SS 5-20 HD . A year an a half old , around 700 rounds 308 on the glass . Has all ways tracked spot on and come back to zero . I just don't know if a scope can loose a zero like what I had happen or if any one has experienced a similar malfunction regardless of brand ?

[C Ward]

It happens , the SS's are typically reliable and they have good customer service .
Had a USO give it up about this time last year , zero shifts and not tracking right .

Were the groups all fired sequentially ? If so I'd remount it and box test it after double checking the rifle and ammo combo with known good glass to be sure before sending it off .

[SA Friday]

Had a bushnell on a pistol a while back that crapped the bed and wiped it on the walls. Did it twice too. Yes, this can happen to a scope.

Cry once.

[67rschev]

It happens , the SS's are typically reliable and they have good customer service .
Had a USO give it up about this time last year , zero shifts and not tracking right .

Were the groups all fired sequentially ? If so I'd remount it and box test it after double checking the rifle and ammo combo with known good glass to be sure before sending it off .

Yes , in that order from top left to bottom right . 6 target sets shot before that set of targets were on the money , groups from .3 - .6 . That is the plan , have an IOR fixed 10 I will bring to the range with me this week to see .

A couple of interesting notes , barrel has target crown and brake does not fit up flush to crown and I do get some carbon build up on muzzle , but find it hard to believe that could be an issue . Also , last two groups of fodder load , was seated .010 further into the lands as my seater plug is not made for the Hornady bullets and I get a little seating variance and sort round to ogive length in sets of five . Again hard to believe , as this gun will shoot even the worst commercial fmjs usually around an inch .

[C Ward]

I'd recheck with both the good and the practice ammo before condemning the scope .

[67rschev]

I'd recheck with both the good and the practice ammo before condemning the scope .

Scope held zero for fifty rounds today of my accuracy loading . Five to re-sight it in , and shot the rest at a somewhat hurried pace to see if I didn't have a heat issue with the barrel last time . Shot on the money printing a .2 , a couple of .3s , and .4s five shot groups for my last five target sets . Barrel too hot to touch when I was through . All adjustments were on , and cranked on the knobs and back . Will box test it next session to be sure with the same loading .

I'm leaning toward the extra OAL to ogive . Wouldn't think an extra .015 - .020 thousandths into the lands would make a good shooting rig , print like that . Will be sure to retest in more depth with the fodder made with the factory seconds and post an update .