How to measure LOP?

Do you own any guns with adjustable LOP?
Also don't forget that LOP changes based on the position you're shooting from.
Your LOP is different when shooting prone, sitting, standing.
Also seasons and the amount of clothing worn in the winter will require a shorter LOP.


I would get into your various shooting positions with an adjustable stock and play around with it till you are comfortable cycling the bolt, single feeding, changing mags, etc.
 
Do you own any guns with adjustable LOP?
Also don't forget that LOP changes based on the position you're shooting from.
Your LOP is different when shooting prone, sitting, standing.
Also seasons and the amount of clothing worn in the winter will require a shorter LOP.


I would get into your various shooting positions with an adjustable stock and play around with it till you are comfortable cycling the bolt, single feeding, changing mags, etc.
Just bullet hosed a pack of hogs with an AR10 708 and with all the pre-hunt practice and load development from the bench, when the squeals, snot, and ass were on, my sight picture was pretty dark and realized the scope was too far back when I shoot all geeked up. So, I lengthened the LOP on the B5 precision stock. Next pack didn't stand a chance!
 
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What body measurements should I be measuring before ordering a 'custom' stock?

And what measurement translates into what theoretical LOP?
The old rule of thumb is to grip the rifle with the finger on the trigger. Place the butt against the elbow. It should fit comfortably or be a little shorter than that using the forearm. If it is longer than that, it will be too long for certain.
 
The old rule of thumb is to grip the rifle with the finger on the trigger. Place the butt against the elbow. It should fit comfortably or be a little shorter than that using the forearm. If it is longer than that, it will be too long for certain.

For the purposes of what the OP asked, yes. This is an acceptable technique.

This is going to be a slight tangent but for every other aspect of adjusting LOP on a precision rifle I despise this technique. It's an old shotgun technique. It was also what I was taught for precision rifles but it never made sense to me. It's like there wasn't a better or more simple answer so the instructor reverted to the only simple rule of thumb that existed despite it coming from a gun where the length of the arm affected the swing of the shotgun. For precision rifles it's a very crude baseline. The reality of PR is that it heavily depends on where the scope is mounted and how, positionally, you're shooting the rifle. When you lay in the prone your arm can bend at the elbow and take up or give more length, to a point, before it starts to affect your firing hand placement and trigger finger position. So the length of your forearm dictating the LOP is barely relevant. That shotgun technique also originated when precision rifles had swept grips, not vertical grips like we have these days so there's a different ergonomic action going on with the wrist.

Yes, understanding the OP isn't setting a gun up right now, he just needs a baseline to put an order in. But in context of setting a gun up, Post #2 provides better advice and it depends on whether or not you're using clip ons where rail space is a factor. If so, I'd drive everything from the front and start with the clip on and work my way backwards. If not, mount the scope so the rear of the ocular housing is directly above, inline with vertical grips. Then let eye relief dictate the LOP. For adj LOP PRS guns I know I'm going to be shooting in a variety of positions so I like to adjust the LOP for proper eye relief in the prone and then shorten it a couple of smidges to accommodate a more vertical neck position like you will have kneeling or standing. I also don't want the cheek piece adjusted for HOB so tightly in the eye box that my face is smashed into the stock to get in the exit pupil. With a slightly shorter LOP/ eye relief and HOB you have a little more forgiveness in head position when shooting awkward positions like weak side. A person also has to think that scopes have a variety of eye relief, tube space for rings, and overall length, and you're going to be wearing different clothing throughout the year so it's almost foolish to let something like your forearm length to dictate the LOP. The scope being mounted correctly has to come first and establish like an anchor everything else.

If you're ordering an old school stock with a swept grip and you aren't able measure using an optic, you're almost better off just using your height as a rough estimate and then using different thickness recoil pads to fine tune. For instance, I'm 6'3" so I always opt for the longest LOP offered by the manufacturer which for a more cookie cutter place like Manners is 14" or so, but I can use a 13 or 13.5". Someone that's 5'10" probably needs a 13", and really short people are just special needs. The reason such a wide variety of body sizes can use same length stocks is because the LOP is really more a function of eye relief before the length of the arm becomes a factor. If you're ordering an expensive stock from a custom stock maker then you should have him measure and fit it for you, based on the action and scope being used.

In reality the LOP doesn't have to be very precise which is why the 1980's shotgun technique persists. Because it's not necessarily wrong. Because the acceptable LOP is so broad and forgiving when it comes to your arm length (not in terms of eye relief) that no one really rebutts it. If you try to "build" a stock on Manners website they don't even give you an option to pick LOP length. It's just standardized across their fixed length models. Probably at 13.5". The only reason I take the time to type all this out is because I've seen junior instructors and people on the internet confuse this rudimentary rule of thumb with ordering a stock with an approximate length vs teaching someone how to setup a purpose built precision rifle that has an adjustment LOP. Two different things. It applies to the first but not really the second. And to the point, you can see in the replies above people talk about adjusting LOP on adjustable stocks instead of understanding approximating stock length for the purposes of putting in an order.
 
For the purposes of what the OP asked, yes. This is an acceptable technique.

This is going to be a slight tangent but for every other aspect of adjusting LOP on a precision rifle I despise this technique. It's an old shotgun technique. It was also what I was taught for precision rifles but it never made sense to me. It's like there wasn't a better or more simple answer so the instructor reverted to the only simple rule of thumb that existed despite it coming from a gun where the length of the arm affected the swing of the shotgun. For precision rifles it's a very crude baseline. The reality of PR is that it heavily depends on where the scope is mounted and how, positionally, you're shooting the rifle. When you lay in the prone your arm can bend at the elbow and take up or give more length, to a point, before it starts to affect your firing hand placement and trigger finger position. So the length of your forearm dictating the LOP is barely relevant. That shotgun technique also originated when precision rifles had swept grips, not vertical grips like we have these days so there's a different ergonomic action going on with the wrist.

Yes, understanding the OP isn't setting a gun up right now, he just needs a baseline to put an order in. But in context of setting a gun up, Post #2 provides better advice and it depends on whether or not you're using clip ons where rail space is a factor. If so, I'd drive everything from the front and start with the clip on and work my way backwards. If not, mount the scope so the rear of the ocular housing is directly above, inline with vertical grips. Then let eye relief dictate the LOP. For adj LOP PRS guns I know I'm going to be shooting in a variety of positions so I like to adjust the LOP for proper eye relief in the prone and then shorten it a couple of smidges to accommodate a more vertical neck position like you will have kneeling or standing. I also don't want the cheek piece adjusted for HOB so tightly in the eye box that my face is smashed into the stock to get in the exit pupil. With a slightly shorter LOP/ eye relief and HOB you have a little more forgiveness in head position when shooting awkward positions like weak side. A person also has to think that scopes have a variety of eye relief, tube space for rings, and overall length, and you're going to be wearing different clothing throughout the year so it's almost foolish to let something like your forearm length to dictate the LOP. The scope being mounted correctly has to come first and establish like an anchor everything else.

If you're ordering an old school stock with a swept grip and you aren't able measure using an optic, you're almost better off just using your height as a rough estimate and then using different thickness recoil pads to fine tune. For instance, I'm 6'3" so I always opt for the longest LOP offered by the manufacturer which for a more cookie cutter place like Manners is 14" or so, but I can use a 13 or 13.5". Someone that's 5'10" probably needs a 13", and really short people are just special needs. The reason such a wide variety of body sizes can use same length stocks is because the LOP is really more a function of eye relief before the length of the arm becomes a factor. If you're ordering an expensive stock from a custom stock maker then you should have him measure and fit it for you, based on the action and scope being used.

In reality the LOP doesn't have to be very precise which is why the 1980's shotgun technique persists. Because it's not necessarily wrong. Because the acceptable LOP is so broad and forgiving when it comes to your arm length (not in terms of eye relief) that no one really rebutts it. If you try to "build" a stock on Manners website they don't even give you an option to pick LOP length. It's just standardized across their fixed length models. Probably at 13.5". The only reason I take the time to type all this out is because I've seen junior instructors and people on the internet confuse this rudimentary rule of thumb with ordering a stock with an approximate length vs teaching someone how to setup a purpose built precision rifle that has an adjustment LOP. Two different things. It applies to the first but not really the second. And to the point, you can see in the replies above people talk about adjusting LOP on adjustable stocks instead of understanding approximating stock length for the purposes of putting in an order.
Even in shotguns the forearm stuff isn’t really used anymore. And with shotguns, proper LOP depends to a degree on the discipline being shot. I.e., trapshooters tend to have a more open body position while skeet shooters tend to mount more across the body, IMO. With shotguns, mount the gun and see where your nose is relative to your thumb. And for low gun upland bird hunting, clearing your chest to get the shotgun to your face without interference is key and one of the reasons that many very old pump guns have been cut.

Using different pads, as you suggested, is a good idea especially when shooting in winter clothes bs a summer t-shirt.

As for rifles, I’m one of those short guys you were talking about (but hey, I’m taller than Frank! lol ). I use chassis and like one that can go down to 12.5” minimum, if necessary. Adjustable LOP on some very nice chassis is wonderful and allows it to be adjusted much easier than stocks.

I just look for good comfortable eye relief while not having to stretch my shoot hand’s forearm out front. I just want comfortable with nice bend at the elbow so I can get a 90 degree trigger finger without cocking my wrist a ton.

Just some random thoughts typing on a dang phone before o go back out work in the yard ( which I try to put off as long as possible).

Cheers.
 
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I don't know what the point of that was. It's the same old tired BS
 
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