Experience with defective scopes that I have to send back for repairs/replacements.
Group size not so great…..suggestions?
- Thread starter BuffaloBill
- Start date
Alex Wheeler
Site $$ Sponsor
115 vlds, rl16, and 450s...
I agree with bedding the chassis, it's obvious looking at the photos the tang is rubbing hard on one side of the action and V block, clamp your barrel in the vice and your indicator on the fore end of your stock leave the rear crew tight and loosen the front screw a quarter turn and watch the indicator for movement of the stock I think you may be surprised at the result, this is the method I learned from Chet Brown the inventor of fiber glass stocks 30 years ago, it has served me well over the years.
I have had quite a few chassis rifles in for accuracy issues, they all had bedding problems even when the machine work in the chassis is perfect the actions are not, bedding cured most of these issues, some custom rifles and all the factory barrels also needed a new crown and a good trigger to get the best performance those particular rifles were capable of.
Free advice, take it or leave it and have a great day.
Alex Wheeler
Site $$ Sponsor
The od of actions are not that good. Borden grinds his, to my knowledge no one else does. Actions are pretty damn good until the ports get cut...
Clancy
Silver $$ Contributor
I start with a bedded rifle, and I do seating depth testing with a luke warm charge, then move on to powder. However, Dusty’s method of doing your powder work at jammed .010 is a good way as well.
H4831 would be better with 115s, H4350 or RL 16 are best in the 105 class, and they’re available almost daily now.
The chronograph needs to stay put away until you’re done or almost done with LD. There’s way too much emphasis on that these days. Good targets don’t lie.
You could always test your scope, but I think proper LD is all you need. I don’t see any tell tale signs of a scope gone awry.
H4831 would be better with 115s, H4350 or RL 16 are best in the 105 class, and they’re available almost daily now.
The chronograph needs to stay put away until you’re done or almost done with LD. There’s way too much emphasis on that these days. Good targets don’t lie.
You could always test your scope, but I think proper LD is all you need. I don’t see any tell tale signs of a scope gone awry.
Dusty Stevens
Shiner
If you start at jammed you cant mess up and go the wrong way nor over pressure it
Clancy
Silver $$ Contributor
Exactly right. More than one way to skin the cat, but starting jammed and backing up is always safest. Most of what I do, I’ve done before with the exact same setup, so I feel safe doing seating at a luke warm charge, but across the board, starting at jam has got to be safer.
BuffaloBill
Silver $$ Contributor
Thanks everyone for all the input. I appreciate it, and am eager to learn. I’m sure you can all relate, sometimes life gets in the way of reporting back immediately.
Boyd,
I have no wind flags as of yet. I see a few diy versions out there. I enjoy building things (like the bipod) but am not opposed to buying commercial ones either. Is there a certain version/brand you recommend?
Beiruty,
Nice of you to model this for me in GRT. One reason my Quickload model seems so far off from yours might be case volume. For my first powder test I used new unfired Lapua brass. I suppose that isn’t ideal. Anyway, the one case I measured was 50.52gr water. Once-fired measured 51.1gr.
Alex,
In your experience, would my 8T stabilize the 115 VLD? The Berger tool shows it to be “marginal”.
X Count, Tommy, & Alex,
About the action/chassis fit: In my first post I made mention of barrel-to-forend movement (measured at the aluminum extension I machined), when loosening the rear screw. I had also tested for movement when loosening the front screw, and observed only .001”. However after reading your message Tommy, I reran that test this afternoon. I think the mistake I made the first time was to only snug back up the rear screw when loosening the front. Today, with the rear screw torqued to 65inlb, loosening the front screw shows 5 thousandths movement.
I don’t want to leave anything on the table, if it’s something I can fix. So I’d like to bed this if you all believe that’s best. I’ve bedded a few stocks before, but never a chassis. For stocks I used years ago, the Brownells Acraglass. Then used Devcon (was it 10100?) on my 243AI back in 2011. Recently I used Marine Tex gray and liked how that was to work with. Is that also appropriate for chassis bedding?
Is there a minimum thickness that should be used? I have a blast cabinet, and could blast that area of the chassis with aluminum oxide, if you think that would be a good move.
Some better results to report:
I did pick up a pound of A4350 yesterday. There was no H4350 on the shelf, nor were there any of the bullets the hive suggested. RKS kindly messaged me about a test method I was not familiar with; a POI/pressure test.
I went ahead and shot 20 rounds (plus two fouling shots, is two sufficient?) using the A4350, 105gr Amax at .004” jam (using your method of finding lands Alex). I tricked charges using an inexpensive Gempro 250. I caught myself at one point, of spacing out on the “one’s“ digit on the scale, and almost seating a bullet one grain light. Despite peoples suggestion to leave the chronograph at home, I confess to having used it again. The velocity recorded for the 41.20 load makes me think I trickled that one to only 40.20. I bet I messed that one up.
Below pic shows points of impact. Aiming points were the line intersections to the left of each hole. The two fouling shots used were loads left from the previous powder/bullet. They struck much closer to the aiming point. I did not adjust windage after firing the first round in this test.
I did my best to minimize shooter error. Boyd had coached me on some points on grasping the stock, etc. I was able to hold crosshairs‘ elevation quite steady. My heartbeat was causing small movement on windage however. Twice during this string of 20 shots, I gave 5mins cooling time. There was some breeze right-to-left. I was shooting on a field drive, fence with weeds on left, and corn (nearly bullet path height) on right.
Edit to add:
I used previously unfired cases on this test, so imagine that will shift results relative to fire-formed? Unfired cases held 50.52gr. Once-fired measure 51.1.
This iPad’s auto “correct” spelling is a pain…..
Another edit to add:
The data for 41.7 is likely also flawed. Hours after assembling these rounds, I realized I’d skipped manufacturing a 41.7. At that point I turned the Gempro 250 back on, and proceeded to trickle a “41.7”. But the velocity measured for that one is suspiciously low. This inexpensive scale does exhibit some form of warm-up drift. I think we should discount that data point.
Boyd,
I have no wind flags as of yet. I see a few diy versions out there. I enjoy building things (like the bipod) but am not opposed to buying commercial ones either. Is there a certain version/brand you recommend?
Beiruty,
Nice of you to model this for me in GRT. One reason my Quickload model seems so far off from yours might be case volume. For my first powder test I used new unfired Lapua brass. I suppose that isn’t ideal. Anyway, the one case I measured was 50.52gr water. Once-fired measured 51.1gr.
Alex,
In your experience, would my 8T stabilize the 115 VLD? The Berger tool shows it to be “marginal”.
X Count, Tommy, & Alex,
About the action/chassis fit: In my first post I made mention of barrel-to-forend movement (measured at the aluminum extension I machined), when loosening the rear screw. I had also tested for movement when loosening the front screw, and observed only .001”. However after reading your message Tommy, I reran that test this afternoon. I think the mistake I made the first time was to only snug back up the rear screw when loosening the front. Today, with the rear screw torqued to 65inlb, loosening the front screw shows 5 thousandths movement.
I don’t want to leave anything on the table, if it’s something I can fix. So I’d like to bed this if you all believe that’s best. I’ve bedded a few stocks before, but never a chassis. For stocks I used years ago, the Brownells Acraglass. Then used Devcon (was it 10100?) on my 243AI back in 2011. Recently I used Marine Tex gray and liked how that was to work with. Is that also appropriate for chassis bedding?
Is there a minimum thickness that should be used? I have a blast cabinet, and could blast that area of the chassis with aluminum oxide, if you think that would be a good move.
Some better results to report:
I did pick up a pound of A4350 yesterday. There was no H4350 on the shelf, nor were there any of the bullets the hive suggested. RKS kindly messaged me about a test method I was not familiar with; a POI/pressure test.
I went ahead and shot 20 rounds (plus two fouling shots, is two sufficient?) using the A4350, 105gr Amax at .004” jam (using your method of finding lands Alex). I tricked charges using an inexpensive Gempro 250. I caught myself at one point, of spacing out on the “one’s“ digit on the scale, and almost seating a bullet one grain light. Despite peoples suggestion to leave the chronograph at home, I confess to having used it again. The velocity recorded for the 41.20 load makes me think I trickled that one to only 40.20. I bet I messed that one up.
Below pic shows points of impact. Aiming points were the line intersections to the left of each hole. The two fouling shots used were loads left from the previous powder/bullet. They struck much closer to the aiming point. I did not adjust windage after firing the first round in this test.
I did my best to minimize shooter error. Boyd had coached me on some points on grasping the stock, etc. I was able to hold crosshairs‘ elevation quite steady. My heartbeat was causing small movement on windage however. Twice during this string of 20 shots, I gave 5mins cooling time. There was some breeze right-to-left. I was shooting on a field drive, fence with weeds on left, and corn (nearly bullet path height) on right.
Edit to add:
I used previously unfired cases on this test, so imagine that will shift results relative to fire-formed? Unfired cases held 50.52gr. Once-fired measure 51.1.
This iPad’s auto “correct” spelling is a pain…..
Another edit to add:
The data for 41.7 is likely also flawed. Hours after assembling these rounds, I realized I’d skipped manufacturing a 41.7. At that point I turned the Gempro 250 back on, and proceeded to trickle a “41.7”. But the velocity measured for that one is suspiciously low. This inexpensive scale does exhibit some form of warm-up drift. I think we should discount that data point.
Attachments
Last edited:
Dusty Stevens
Shiner
Looks like your gun holds the exact same elevation from 39-42gr of powder. Thats the most creedmoor thing ive ever seen
BuffaloBill
Silver $$ Contributor
Here are the velocities recorded for the above test:
Velocity measurements were not all monotonic in a couple areas.
39.0 2853
39.2 2835
39.4 2853
39.6 2889
39.8 2914
40.0 2933
40.2 2957
40.4 2980
40.6 2984
40.8 3008
41.0 3032
41.2 2953 (makes me wonder if I spaced out trickling this charge at 40.2 instead of 41.2?)
41.3 3029
41.4 3079
41.5 3084
41.6 3087
41.7 3033
41.8 3104
41.9 3118
42.0 3118
Another edit to add:
The data for 41.7 is likely also flawed. Hours after assembling these rounds, I realized I’d skipped manufacturing a 41.7. At that point I turned the Gempro 250 back on, and proceeded to trickle a “41.7”. But the velocity measured for that one is suspiciously low. This inexpensive scale does exhibit some form of warm-up drift. I think we should discount that data point.
Velocity measurements were not all monotonic in a couple areas.
39.0 2853
39.2 2835
39.4 2853
39.6 2889
39.8 2914
40.0 2933
40.2 2957
40.4 2980
40.6 2984
40.8 3008
41.0 3032
41.2 2953 (makes me wonder if I spaced out trickling this charge at 40.2 instead of 41.2?)
41.3 3029
41.4 3079
41.5 3084
41.6 3087
41.7 3033
41.8 3104
41.9 3118
42.0 3118
Another edit to add:
The data for 41.7 is likely also flawed. Hours after assembling these rounds, I realized I’d skipped manufacturing a 41.7. At that point I turned the Gempro 250 back on, and proceeded to trickle a “41.7”. But the velocity measured for that one is suspiciously low. This inexpensive scale does exhibit some form of warm-up drift. I think we should discount that data point.
Last edited:
BuffaloBill
Silver $$ Contributor
Would I have been better off testing at a greater distance?
Dusty Stevens
Shiner
I think so. I also think you can space it out a bit to save some components and shoot 2 of each to get more data
BuffaloBill
Silver $$ Contributor
2 or 3 hundred yds maybe?
Dusty Stevens
Shiner
Id go to 200 so the wind doesnt cloud your results more. Even 2 shots of each at 100 would probably work. Skip .3gr in powder. Do the .1gr skip once you find a good spot you like
BuffaloBill
Silver $$ Contributor
I do not. But will be keeping an eye out for these.
Mr. Buffalo Bill
Marine Tex epoxy works great nice and thick stays pretty much in place, almost any 2-part epoxy that's thick kind of putty like will suffice don't use any of the quick type unless you're real fast and have everything prepared ahead of time or you will have a mess to clean up.
On aluminum bedding blocks and Chassis V blocks I use a small electric vibrating etching tool the kind you can mark or engrave on hard surfaces with, it works like a miniature jack hammer leaving tiny dimples over the entire surface to be bedded, once you get the hang of it you can prepare the bedding area in minutes.
I prefer to skim bed over the aluminum blocks unless I need thicker bedding for a specific purpose.
.005 movement in your bedding can cause groups like you shot in the photos, I would advise you to fix your gun then follow the loading and shooting advice from some darn good shooters on here, wind flags are a must, but you can get by with a ribbon tied on a surveyor's stake if that's what you have to work with.
Good shooting
Marine Tex epoxy works great nice and thick stays pretty much in place, almost any 2-part epoxy that's thick kind of putty like will suffice don't use any of the quick type unless you're real fast and have everything prepared ahead of time or you will have a mess to clean up.
On aluminum bedding blocks and Chassis V blocks I use a small electric vibrating etching tool the kind you can mark or engrave on hard surfaces with, it works like a miniature jack hammer leaving tiny dimples over the entire surface to be bedded, once you get the hang of it you can prepare the bedding area in minutes.
I prefer to skim bed over the aluminum blocks unless I need thicker bedding for a specific purpose.
.005 movement in your bedding can cause groups like you shot in the photos, I would advise you to fix your gun then follow the loading and shooting advice from some darn good shooters on here, wind flags are a must, but you can get by with a ribbon tied on a surveyor's stake if that's what you have to work with.
Good shooting
BuffaloBill
Silver $$ Contributor
I used to have an engraver like that. Will have to pick one up. Thanks for the advice. This Tikka T3 uses a non traditional recoil lug setup. This Bravo chassis has a steel “lug” pressed(?) into it’s aluminum structure, that feels to be, a fairly precision fit to the cross slot in the action. But I imagine the fit can’t be perfect. I’m not sure when bedding, how to handle this recoil lug area. Any suggestions?
Those kinds of recoil lugs can cause problems. Make sure the lug is not moving. As others have said, it may need bedding.
Try some other bullets and try to do your ladder further than 100 yds if you can or use your chrono.
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